Files inaccessible on Android client 3.16.1 when in airplane mode

In the Nextcloud client on Android all relevant files are marked with a small white arrow in a green circle. But when I want to reopen one e.g. from Keepass using the stored location “content://org.nextcloud.documents/documentXXXXXXXXX%2F20” this fails if the Server is inaccessible e.g. in airplane mode.

Is there a better solution than to copy the files manually to a local folder while online? I was expecting all files to automatically be available offline.

I got the above mentioned location by opening the file from Keepass and on top Level selecting Nextcloud as provider. A file selected by doing so is still unreadable when in Airplane mode.

If I click on the same file (.ending kdbx for Keepass) in the Nextcloud Android client (currently 3.17.0, phone still in airplane mode) I get a message that the selected file could not be synchronized but then Keepass is started. The path to the file supplied by doing this is “content://org.nextcloud.files/external_files/9876-5432/Android/media/com.nextcloud.client/nextcloud/xxx@yyy,/Database.kdbx” which is different from the one I get when selecting the file from the external app. I can open this file even when In airplane mode.

Which of the 2 paths is correct to refer to a synchronised version of the file? And what would be the correct way to select a file from Nextcloud in another Android app?