Failed to login cause of http polling url vps->apache2->docker-compose->Nextcloud 22.2.0

Support intro

Hi everyone. I have a nextcloud installation in docker-compose behind a apache webserver on a ubuntu vps. Unfortunally I am not further able to login from windows computers (I didn’t try it from the ubuntu one, because both are further connected and I’m scared to disconnect). The response from the client is

Die Polling-URL beginnt nicht mit HTTPS, obwohl die Anmelde-URL mit HTTPS beginnt. Die Anmeldung ist nicht möglich, da dies ein Sicherheitsproblem darstellen könnte. Bitte wenden Sie sich an Ihren Administrator

;

Nextcloud version: 22.2.0
Operating system and version: 21.04
Apache or nginx version: 2.4.46
PHP version: 8.0.11

The issue you are facing: When I try to login from a winows client I got the following error message:

Die Polling-URL beginnt nicht mit HTTPS, obwohl die Anmelde-URL mit HTTPS beginnt. Die Anmeldung ist nicht möglich, da dies ein Sicherheitsproblem darstellen könnte. Bitte wenden Sie sich an Ihren Administrator

Is this the first time you’ve seen this error? Y: the clients were all running fine. One time the windows client shows error and I tried to login new. Between the last login and this, there were some updates of the docker container/image. After latest update of nextcloud it runs further fine.

Steps to replicate it:

  1. try to login from a windows client

The output of your Nextcloud log in Roaming>Nextcloud>logs:

2021-10-08 20:20:30:739 [ info nextcloud.gui.application ]:	"################## Nextcloud locale:[de_DE] ui_lang:[] version:[3.3.5stable-Win64 (build 20210930)] os:[Windows 10 (10.0)]"
2021-10-08 20:20:30:752 [ info nextcloud.gui.application ]:	Using "de_DE" translation
2021-10-08 20:20:30:839 [ info nextcloud.gui.application ]:	VFS windows plugin is available
2021-10-08 20:20:30:858 [ info nextcloud.gui.application ]:	VFS suffix plugin is available
2021-10-08 20:20:30:860 [ debug nextcloud.gui.socketapi ]	[ OCC::SocketApi::SocketApi ]:	creating "//./pipe" true
2021-10-08 20:20:30:860 [ info nextcloud.gui.socketapi ]:	server started, listening at  "\\\\.\\pipe\\nextcloud-username"
2021-10-08 20:20:30:861 [ info nextcloud.gui.folder.manager ]:	setting remote poll timer interval to 30000 msec
2021-10-08 20:20:30:861 [ info nextcloud.gui.account.manager ]:	Migrate: restoreFromLegacySettings, checking settings group "Nextcloud"
2021-10-08 20:20:30:861 [ info nextcloud.gui.account.manager ]:	Migrate: checking old config  "C:/Users/Username/AppData/Roaming/ownCloud/owncloud.cfg"
2021-10-08 20:20:30:936 [ info nextcloud.gui.folder.manager ]:	Setup folders from  "C:/Users/Username/AppData/Roaming/Nextcloud/folders" (migration)
2021-10-08 20:20:30:937 [ info nextcloud.sync.clientproxy ]:	Set proxy configuration to use the preferred system proxy for http tcp connections
2021-10-08 20:20:30:958 [ debug nextcloud.gui.updater ]	[ OCC::Updater::create ]:	QUrl("https://updates.nextcloud.org/client/?version=3.3.5.20210930&platform=win32&osRelease=windows&osVersion=10&kernelVersion=10.0.19042&oem=Nextcloud&buildArch=x86_64&currentArch=x86_64&versionsuffix=stable-Win64&updatesegment=89&msi=true")
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:312: TypeError: Cannot read property 'avatar' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:321: TypeError: Cannot read property 'isConnected' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:333: TypeError: Cannot read property 'isConnected' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:348: TypeError: Cannot read property 'statusIcon' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:346: TypeError: Cannot read property 'isConnected' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:372: TypeError: Cannot read property 'name' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:381: TypeError: Cannot read property 'isConnected' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:390: TypeError: Cannot read property 'statusEmoji' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:388: TypeError: Cannot read property 'statusEmoji' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:398: TypeError: Cannot read property 'statusMessage' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:396: TypeError: Cannot read property 'statusMessage' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:441: TypeError: Cannot read property 'hasLocalFolder' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:459: TypeError: Cannot read property 'isConnected' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:458: TypeError: Cannot read property 'hasLocalFolder' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:470: TypeError: Cannot read property 'isConnected' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:484: TypeError: Cannot read property 'serverHasTalk' of null
2021-10-08 20:20:33:045 [ warning default ]:	qrc:/qml/src/gui/tray/Window.qml:580: ReferenceError: activityModel is not defined
2021-10-08 20:20:33:057 [ info nextcloud.gui.application ]:	No configured folders yet, starting setup wizard
2021-10-08 20:20:33:324 [ info nextcloud.gui.wizard.webviewpage ]:	Time for a webview!
2021-10-08 20:20:33:692 [ warning default ]:	Please register the custom scheme 'nc' via QWebEngineUrlScheme::registerScheme() before installing the custom scheme handler.
2021-10-08 20:20:33:768 [ debug nextcloud.gui.wizard ]	[ OCC::OwncloudWizard::slotCurrentPageChanged ]:	Current Wizard page changed to  0
2021-10-08 20:20:34:136 [ info nextcloud.gui.updater ]:	Checking for available update
2021-10-08 20:20:34:138 [ info nextcloud.sync.accessmanager ]:	2 "" "https://updates.nextcloud.org/client/?version=3.3.5.20210930&platform=win32&osRelease=windows&osVersion=10&kernelVersion=10.0.19042&oem=Nextcloud&buildArch=x86_64&currentArch=x86_64&versionsuffix=stable-Win64&updatesegment=89&msi=true" has X-Request-ID "b4405653-9cbb-4f82-8470-78a2dbe74e30"
2021-10-08 20:20:34:138 [ debug nextcloud.sync.cookiejar ]	[ OCC::CookieJar::cookiesForUrl ]:	QUrl("https://updates.nextcloud.org/client/?version=3.3.5.20210930&platform=win32&osRelease=windows&osVersion=10&kernelVersion=10.0.19042&oem=Nextcloud&buildArch=x86_64&currentArch=x86_64&versionsuffix=stable-Win64&updatesegment=89&msi=true") requests: ()
2021-10-08 20:20:34:141 [ info nextcloud.gui.socketapi ]:	New connection QLocalSocket(0x1955d284d00)
2021-10-08 20:20:36:960 [ debug nextcloud.gui.wizard ]	[ OCC::OwncloudWizard::slotCurrentPageChanged ]:	Current Wizard page changed to  1
2021-10-08 20:20:47:374 [ debug nextcloud.gui.wizard ]	[ OCC::OwncloudSetupWizard::slotCheckServer ]:	Trying to look up system proxy
2021-10-08 20:20:47:379 [ info nextcloud.gui.wizard ]:	No system proxy set by OS
2021-10-08 20:20:47:382 [ info nextcloud.sync.accessmanager ]:	2 "" "https://domain.tld/owncloud/status.php" has X-Request-ID "03369a7e-bce3-442d-aca3-a7b2f251fa2f"
2021-10-08 20:20:47:382 [ debug nextcloud.sync.cookiejar ]	[ OCC::CookieJar::cookiesForUrl ]:	QUrl("https://domain.tld/owncloud/status.php") requests: ()
2021-10-08 20:20:47:383 [ info nextcloud.sync.networkjob ]:	OCC::CheckServerJob created for "https://domain.tld/owncloud/" + "status.php" "OCC::OwncloudSetupWizard"
2021-10-08 20:20:51:455 [ info nextcloud.gui.updater ]:	Version info arrived: Your version: 217022704622265586 Skipped version: 0 "" Available version: 0 "" Available version string: "" Web url: "" Download url: ""
2021-10-08 20:20:51:456 [ info nextcloud.gui.updater ]:	No version information available at the moment
2021-10-08 20:20:59:698 [ info nextcloud.sync.networkjob.checkserver ]:	status.php returns:  QJsonDocument({"edition":"","extendedSupport":false,"installed":true,"maintenance":false,"needsDbUpgrade":false,"productname":"Nextcloud","version":"22.2.0.2","versionstring":"22.2.0"})   QNetworkReply::NoError  Reply:  QNetworkReplyHttpImpl(0x1955ce8d850)
2021-10-08 20:20:59:698 [ debug nextcloud.gui.wizard ]	[ OCC::OwncloudWizard::appendToConfigurationLog ]:	Setup-Log:  "<font color=\"green\">Erfolgreich mit  https://domain.tld/owncloud/ verbunden: Nextcloud Version 22.2.0 (22.2.0.2)</font><br/><br/>"
2021-10-08 20:20:59:698 [ info nextcloud.sync.networkjob.determineauthtype ]:	Determining auth type for QUrl("https://domain.tld/owncloud/remote.php/dav/files//")
2021-10-08 20:20:59:698 [ info nextcloud.sync.accessmanager ]:	2 "" "https://domain.tld/owncloud/" has X-Request-ID "e03acb24-40e3-445d-82f1-154b07ef7a80"
2021-10-08 20:20:59:698 [ debug nextcloud.sync.cookiejar ]	[ OCC::CookieJar::cookiesForUrl ]:	QUrl("https://domain.tld/owncloud/") requests: (QNetworkCookie("oc_sessionPassphrase=2SUbTmQcb5y0EcHW1DYVc8QhIcN%2FcMOec7WBZ3HtqjOiEi3O6iL%2B%2BDpG4%2BRhF%2B3Cr7%2BZkrdnAZDIZ5mUorJM4p3fICMDaY1IMeYJVb00%2FnqTgCcles27GIB4spEFqBpU; HttpOnly; domain=domain.tld; path=/owncloud"), QNetworkCookie("oc01zjyg7ro7=8a9d22168c91f743f2a37ed2d346d0cb; HttpOnly; domain=domain.tld; path=/owncloud"), QNetworkCookie("nc_sameSiteCookielax=true; HttpOnly; expires=Fri, 31-Dec-2100 23:59:59 GMT; domain=domain.tld; path=/owncloud"), QNetworkCookie("nc_sameSiteCookiestrict=true; HttpOnly; expires=Fri, 31-Dec-2100 23:59:59 GMT; domain=domain.tld; path=/owncloud"))
2021-10-08 20:20:59:699 [ info nextcloud.sync.networkjob ]:	OCC::SimpleNetworkJob created for "https://domain.tld/owncloud/" + "" ""
2021-10-08 20:20:59:699 [ info nextcloud.sync.accessmanager ]:	6 "PROPFIND" "https://domain.tld/owncloud/remote.php/dav/files//" has X-Request-ID "2a8747b8-56a4-484d-b58b-3aee09b0ca6c"
2021-10-08 20:20:59:699 [ debug nextcloud.sync.cookiejar ]	[ OCC::CookieJar::cookiesForUrl ]:	QUrl("https://domain.tld/owncloud/remote.php/dav/files//") requests: (QNetworkCookie("oc_sessionPassphrase=2SUbTmQcb5y0EcHW1DYVc8QhIcN%2FcMOec7WBZ3HtqjOiEi3O6iL%2B%2BDpG4%2BRhF%2B3Cr7%2BZkrdnAZDIZ5mUorJM4p3fICMDaY1IMeYJVb00%2FnqTgCcles27GIB4spEFqBpU; HttpOnly; domain=domain.tld; path=/owncloud"), QNetworkCookie("oc01zjyg7ro7=8a9d22168c91f743f2a37ed2d346d0cb; HttpOnly; domain=domain.tld; path=/owncloud"), QNetworkCookie("nc_sameSiteCookielax=true; HttpOnly; expires=Fri, 31-Dec-2100 23:59:59 GMT; domain=domain.tld; path=/owncloud"), QNetworkCookie("nc_sameSiteCookiestrict=true; HttpOnly; expires=Fri, 31-Dec-2100 23:59:59 GMT; domain=domain.tld; path=/owncloud"))
2021-10-08 20:20:59:699 [ info nextcloud.sync.networkjob ]:	OCC::SimpleNetworkJob created for "https://domain.tld/owncloud/" + "" ""
2021-10-08 20:20:59:699 [ info nextcloud.sync.accessmanager ]:	2 "" "https://domain.tld/owncloud/ocs/v2.php/cloud/capabilities?format=json" has X-Request-ID "ce819847-216c-488c-83d7-07c76c4bf2da"
2021-10-08 20:20:59:700 [ debug nextcloud.sync.cookiejar ]	[ OCC::CookieJar::cookiesForUrl ]:	QUrl("https://domain.tld/owncloud/ocs/v2.php/cloud/capabilities?format=json") requests: (QNetworkCookie("oc_sessionPassphrase=2SUbTmQcb5y0EcHW1DYVc8QhIcN%2FcMOec7WBZ3HtqjOiEi3O6iL%2B%2BDpG4%2BRhF%2B3Cr7%2BZkrdnAZDIZ5mUorJM4p3fICMDaY1IMeYJVb00%2FnqTgCcles27GIB4spEFqBpU; HttpOnly; domain=domain.tld; path=/owncloud"), QNetworkCookie("oc01zjyg7ro7=8a9d22168c91f743f2a37ed2d346d0cb; HttpOnly; domain=domain.tld; path=/owncloud"), QNetworkCookie("nc_sameSiteCookielax=true; HttpOnly; expires=Fri, 31-Dec-2100 23:59:59 GMT; domain=domain.tld; path=/owncloud"), QNetworkCookie("nc_sameSiteCookiestrict=true; HttpOnly; expires=Fri, 31-Dec-2100 23:59:59 GMT; domain=domain.tld; path=/owncloud"))
2021-10-08 20:20:59:700 [ info nextcloud.sync.networkjob ]:	OCC::JsonApiJob created for "https://domain.tld/owncloud/" + "/ocs/v2.php/cloud/capabilities" "OCC::DetermineAuthTypeJob"
2021-10-08 20:20:59:700 [ debug nextcloud.sync.networkjob ]	[ OCC::AbstractNetworkJob::slotFinished ]:	Network job OCC::CheckServerJob finished for "status.php"
2021-10-08 20:21:00:259 [ info nextcloud.sync.networkjob.jsonapi ]:	JsonApiJob of QUrl("https://domain.tld/owncloud/ocs/v2.php/cloud/capabilities?format=json") FINISHED WITH STATUS "OK"
2021-10-08 20:21:00:259 [ debug nextcloud.sync.networkjob ]	[ OCC::AbstractNetworkJob::slotFinished ]:	Network job OCC::JsonApiJob finished for "/ocs/v2.php/cloud/capabilities"
2021-10-08 20:21:00:264 [ warning nextcloud.sync.networkjob.determineauthtype ]:	Unknown WWW-Authenticate reply to auth-test PROPFIND: "basic realm=\"nextcloud\", charset=\"utf-8\""
2021-10-08 20:21:00:264 [ debug nextcloud.sync.networkjob ]	[ OCC::AbstractNetworkJob::slotFinished ]:	Network job OCC::SimpleNetworkJob finished for ""
2021-10-08 20:21:00:691 [ warning nextcloud.sync.networkjob ]:	OCC::SimpleNetworkJob(0x1955cbe7950) HTTPS->HTTP downgrade detected!
2021-10-08 20:21:00:691 [ info nextcloud.sync.networkjob.determineauthtype ]:	Auth type for QUrl("https://domain.tld/owncloud/remote.php/dav/files//") is OCC::DetermineAuthTypeJob::LoginFlowV2
2021-10-08 20:21:00:692 [ info nextcloud.sync.accessmanager ]:	4 "" "https://domain.tld/owncloud/index.php/login/v2" has X-Request-ID "259b0d40-8989-4f80-a601-816160f2b12e"
2021-10-08 20:21:00:692 [ debug nextcloud.sync.cookiejar ]	[ OCC::CookieJar::cookiesForUrl ]:	QUrl("https://domain.tld/owncloud/index.php/login/v2") requests: (QNetworkCookie("oc_sessionPassphrase=2SUbTmQcb5y0EcHW1DYVc8QhIcN%2FcMOec7WBZ3HtqjOiEi3O6iL%2B%2BDpG4%2BRhF%2B3Cr7%2BZkrdnAZDIZ5mUorJM4p3fICMDaY1IMeYJVb00%2FnqTgCcles27GIB4spEFqBpU; HttpOnly; domain=domain.tld; path=/owncloud"), QNetworkCookie("oc01zjyg7ro7=8a9d22168c91f743f2a37ed2d346d0cb; HttpOnly; domain=domain.tld; path=/owncloud"), QNetworkCookie("nc_sameSiteCookielax=true; HttpOnly; expires=Fri, 31-Dec-2100 23:59:59 GMT; domain=domain.tld; path=/owncloud"), QNetworkCookie("nc_sameSiteCookiestrict=true; HttpOnly; expires=Fri, 31-Dec-2100 23:59:59 GMT; domain=domain.tld; path=/owncloud"))
2021-10-08 20:21:00:693 [ info nextcloud.sync.networkjob ]:	OCC::SimpleNetworkJob created for "https://domain.tld/owncloud/" + "" ""
2021-10-08 20:21:00:695 [ debug nextcloud.gui.wizard ]	[ OCC::OwncloudWizard::slotCurrentPageChanged ]:	Current Wizard page changed to  4
2021-10-08 20:21:00:696 [ debug nextcloud.sync.networkjob ]	[ OCC::AbstractNetworkJob::slotFinished ]:	Network job OCC::SimpleNetworkJob finished for ""
2021-10-08 20:21:00:869 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:21:00:869 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:21:00:869 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:21:04:317 [ warning nextcloud.sync.credentials.flow2auth ]:	Can not poll endpoint because the returned url "" does not start with https
2021-10-08 20:21:04:317 [ debug nextcloud.sync.networkjob ]	[ OCC::AbstractNetworkJob::slotFinished ]:	Network job OCC::SimpleNetworkJob finished for ""
2021-10-08 20:21:30:864 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:21:30:864 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:21:30:864 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:22:00:864 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:22:00:864 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:22:00:864 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:22:30:885 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:22:30:885 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:22:30:885 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:23:00:893 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:23:00:893 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:23:00:893 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:23:30:900 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:23:30:900 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:23:30:900 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:24:00:916 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:24:00:916 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:24:00:916 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:24:30:937 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:24:30:937 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:24:30:937 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:25:00:952 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:25:00:952 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:25:00:952 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:25:30:945 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:25:30:945 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:25:30:945 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:26:00:962 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:26:00:962 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:26:00:962 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:26:30:968 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:26:30:968 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:26:30:968 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:27:00:969 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:27:00:969 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:27:00:969 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:27:30:967 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:27:30:967 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:27:30:967 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:28:00:962 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:28:00:962 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:28:00:962 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:28:30:959 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:28:30:959 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:28:30:959 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:29:00:964 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:29:00:964 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:29:00:964 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:29:30:967 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:29:30:967 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:29:30:967 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:30:00:966 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:30:00:966 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:30:00:966 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:30:30:966 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:30:30:966 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:30:30:966 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:31:00:968 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:31:00:969 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:31:00:969 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:31:30:959 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:31:30:959 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:31:30:959 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:32:00:960 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:32:00:960 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:32:00:960 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:32:30:970 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:32:30:970 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:32:30:970 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:33:00:999 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:33:00:999 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:33:00:999 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:33:30:994 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:33:30:994 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:33:30:994 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:34:01:010 [ info nextcloud.gui.folder.manager ]:	Etag poll timer timeout
2021-10-08 20:34:01:010 [ info nextcloud.gui.folder.manager ]:	Folders to sync: 0
2021-10-08 20:34:01:010 [ info nextcloud.gui.folder.manager ]:	Number of folders that don't use push notifications: 0
2021-10-08 20:34:03:332 [ info nextcloud.gui.socketapi ]:	New connection QLocalSocket(0x1955ce8d6d0)
2021-10-08 20:34:03:333 [ info nextcloud.gui.socketapi ]:	Received SocketAPI message <-- "GET_STRINGS:CONTEXT_MENU_TITLE" from QLocalSocket(0x1955ce8d6d0)
2021-10-08 20:34:03:334 [ debug nextcloud.gui.socketapi ]	[ OCC::SocketListener::sendMessage ]:	Sending SocketAPI message --> "GET_STRINGS:BEGIN" to QLocalSocket(0x1955ce8d6d0)
2021-10-08 20:34:03:334 [ debug nextcloud.gui.socketapi ]	[ OCC::SocketListener::sendMessage ]:	Sending SocketAPI message --> "STRING:CONTEXT_MENU_TITLE:Nextcloud" to QLocalSocket(0x1955ce8d6d0)
2021-10-08 20:34:03:334 [ debug nextcloud.gui.socketapi ]	[ OCC::SocketListener::sendMessage ]:	Sending SocketAPI message --> "GET_STRINGS:END" to QLocalSocket(0x1955ce8d6d0)
2021-10-08 20:34:03:334 [ info nextcloud.gui.socketapi ]:	Received SocketAPI message <-- "GET_MENU_ITEMS:C:\\Users\\username\\AppData\\Roaming\\Nextcloud\\logs\\20211008_2020_owncloud.log.0" from QLocalSocket(0x1955ce8d6d0)
2021-10-08 20:34:03:335 [ debug nextcloud.gui.socketapi ]	[ OCC::SocketListener::sendMessage ]:	Sending SocketAPI message --> "GET_MENU_ITEMS:BEGIN" to QLocalSocket(0x1955ce8d6d0)
2021-10-08 20:34:03:335 [ debug nextcloud.gui.socketapi ]	[ OCC::SocketListener::sendMessage ]:	Sending SocketAPI message --> "GET_MENU_ITEMS:END" to QLocalSocket(0x1955ce8d6d0)
2021-10-08 20:34:03:451 [ info nextcloud.gui.socketapi ]:	Lost connection  QLocalSocket(0x1955ce8d6d0)

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

<?php
$CONFIG = array (
  'updatechecker' => false,
  'instanceid' => 'oc01zjyg....',
  'passwordsalt' => 'password',
  'secret' => 'secretstring',
  'overwrite.cli.url' => 'https://domain.tld/owncloud',
  'overwritewebroot' => 'owncloud',
  'overwritehost' => 'domain.tld',
  'overwriteprotocol ' => 'https',
  'dbtype' => 'mysql',
  'version' => '22.2.0.2',
  'dbname' => 'owncloud',
  'dbhost' => 'website-db',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'owncloud',
  'dbpassword' => 'password',
  'logtimezone' => 'UTC',
  'installed' => true,
  'mail_domain' => 'domain.tld',
  'mail_from_address' => 'webmaster',
  'mail_smtpmode' => 'php',
  'loglevel' => 3,
  'theme' => '',
  '

The output of your Container log in docker-compose logs -f:

nextcloud_1   | 172.22.0.1 - - [08/Oct/2021:18:20:53 +0000] "GET /status.php HTTP/1.1" 200 1755 "-" "Mozilla/5.0 (Windows) mirall/3.3.5stable-Win64 (build 20210930) (Nextcloud, windows-10.0.19042 ClientArchitecture: x86_64 OsArchitecture: x86_64)"
nextcloud_1   | 172.22.0.1 - - [08/Oct/2021:18:20:59 +0000] "GET /ocs/v2.php/cloud/capabilities?format=json HTTP/1.1" 200 1232 "-" "Mozilla/5.0 (Windows) mirall/3.3.5stable-Win64 (build 20210930) (Nextcloud, windows-10.0.19042 ClientArchitecture: x86_64 OsArchitecture: x86_64)"
nextcloud_1   | 172.22.0.1 - - [08/Oct/2021:18:20:59 +0000] "PROPFIND /remote.php/dav/files/ HTTP/1.1" 401 1234 "-" "Mozilla/5.0 (Windows) mirall/3.3.5stable-Win64 (build 20210930) (Nextcloud, windows-10.0.19042 ClientArchitecture: x86_64 OsArchitecture: x86_64)"
nextcloud_1   | 172.22.0.1 - - [08/Oct/2021:18:20:59 +0000] "GET / HTTP/1.1" 302 966 "-" "Mozilla/5.0 (Windows) mirall/3.3.5stable-Win64 (build 20210930) (Nextcloud, windows-10.0.19042 ClientArchitecture: x86_64 OsArchitecture: x86_64)"

The docker-compose.yml

version: '2'

services:

  website-db:
    image: mysql:8.0.26
    restart: always
    command: --default-authentication-plugin=mysql_native_password
    environment:
      MYSQL_ROOT_PASSWORD: secretpassword
    volumes:
      - /etc/localtime:/etc/localtime:ro
      - /etc/timezone:/etc/timezone:ro
      - ./database:/var/lib/mysql
    networks:
      - default

#  phpmyadmin:
#    depends_on:
#      - website-db
#    image: phpmyadmin:5.1.1
#    restart: always
#    ports:
#      - '7997:80'
#    environment:
#      PMA_HOST: website-db
#      UPLOAD_LIMIT: 2G
#    networks:
#      - default

  nextcloud:
    image: nextcloud:22.2.0-apache
    ports:
      - 7996:80
    restart: unless-stopped
    depends_on:
      - website-db
    environment:
        APACHE_DISABLE_REWRITE_IP: 1
        OVERWRITEWEBROOT: owncloud
        OVERWRITEHOST: domain.tld
        OVERWRITEPROTOCOL: https
    volumes:
      - ./nextcloud/data:/var/www/html/data
      - ./nextcloud/config:/var/www/html/config
      - ./nextcloud/custom_apps:/var/www/html/custom_apps
    networks:
      - default

Hint: It was earlier a owncloud installation, I changed it to nextcloud. The subfolder is further called owncloud/ cause it would be lots of work to change the url in all clients syncing calendar and contacts.

Thank you in advance