CalDAV reminders not working on macOS Big Sur (11.6), calendar works, iOS works, certificate OK

Nextcloud version (eg, 20.0.5): 22.2.3snap1
Operating system and version (eg, Ubuntu 20.04): Ubuntu 20.04.3 LTS
Apache or nginx version (eg, Apache 2.4.25): apache behind nginx reverse proxy
PHP version (eg, 7.4): don't know

The issue you are facing:

I can’t get taks to sync to Reminders.app on macOS Big Sur (11.6) using CalDAV, however:

  1. Calendar events do sync
  2. CalDAV does work for both calendar & tasks on iOS14
  3. It’s not a certificate issue (I’m using letsencrypt, AND see points 1. and 2. above)
  4. It’s not the known little snitch / Big Sur 11.0 error - I have the same issue booting in safe mode.

Furthermore, the macOS client (showing up as macOS/11.6.1 (20G224) CalendarAgent/954) seems to PROPFIND the same resource as iOS (/remote.php/dav/principals/users/USERNAME/), but then fails and tries other resources using a different useragent string (`iOS/11.6.1 (20G224) remindd/1.0). See access.log below.

I hope somebody can help me and has some idea as to what’s going on! :slight_smile: It’s driving me nuts :exploding_head: I’d really like to use nextcloud for my personal notes etc. to own my data a bit more.

Is this the first time you’ve seen this error? (Y/N): Y

Steps to replicate it:

on Nextcloud:

  1. Install nextcloud Calendar & Tasks apps
  2. Go to Calendar app > Settings & Import > Copy iOS/MacOS CalDAV address (=https://FQDN/remote.php/dav/principals/users/USERNAME/)

on macOS:

  1. configure new CalDAV account as ‘Advanced’ account type, username: USERNAME, password: password, server address: https://FQDN/, server path: /remote.php/dav/principals/users/USERNAME/, port 443, Use SSL enabled;
  2. After adding, ‘Use with Calendar’ is ticked, ‘Use with Reminders’ is not
  3. Calendar events sync, but Tasks/Reminders do not

on iOS:

  1. Add the account using the same settings as on macOS.
  2. After adding, both ‘Use with Calendar’ and ‘Use with Reminders’ are ticked
  3. Both Calendar events & Tasks/reminders sync

The output of your Nextcloud log in Admin > Logging:

no logging shown

The output of your Apache/nginx/system log in /var/log/____:

When I enable the account to macOS I get:

ipv4.macos - USERNAME [19/Dec/2021:21:52:58 +0100] "PROPFIND /remote.php/dav/calendars/USERNAME/ HTTP/1.1" 207 1428 "-" "macOS/11.6.1 (20G224) CalendarAgent/954"
ipv4.macos - USERNAME [19/Dec/2021:21:52:59 +0100] "PROPFIND /remote.php/dav/calendars/USERNAME/inbox/ HTTP/1.1" 207 260 "-" "macOS/11.6.1 (20G224) CalendarAgent/954"
ipv4.macos - USERNAME [19/Dec/2021:21:52:59 +0100] "PROPFIND /remote.php/dav/calendars/USERNAME/inbox/ HTTP/1.1" 207 260 "-" "macOS/11.6.1 (20G224) CalendarAgent/954"
ipv4.macos - USERNAME [19/Dec/2021:21:52:59 +0100] "REPORT /remote.php/dav/principals/users/USERNAME/ HTTP/1.1" 207 565 "-" "macOS/11.6.1 (20G224) CalendarAgent/954"
ipv4.macos - - [19/Dec/2021:21:53:00 +0100] "PROPFIND /.well-known/caldav HTTP/1.1" 301 257 "-" "iOS/11.6.1 (20G224) remindd/1.0"
ipv4.macos - - [19/Dec/2021:21:53:00 +0100] "PROPFIND / HTTP/1.1" 405 0 "-" "iOS/11.6.1 (20G224) remindd/1.0"
ipv4.macos - - [19/Dec/2021:21:53:00 +0100] "PROPFIND /principals/ HTTP/1.1" 405 225 "-" "iOS/11.6.1 (20G224) remindd/1.0"
ipv4.macos - - [19/Dec/2021:21:53:00 +0100] "PROPFIND /calendar/dav/USERNAME/user/ HTTP/1.1" 405 225 "-" "iOS/11.6.1 (20G224) remindd/1.0"
ipv4.macos - - [19/Dec/2021:21:53:03 +0100] "PROPFIND /.well-known/caldav HTTP/1.1" 301 257 "-" "iOS/11.6.1 (20G224) remindd/1.0"
ipv4.macos - - [19/Dec/2021:21:53:04 +0100] "PROPFIND / HTTP/1.1" 405 0 "-" "iOS/11.6.1 (20G224) remindd/1.0"
ipv4.macos - - [19/Dec/2021:21:53:04 +0100] "PROPFIND /principals/ HTTP/1.1" 405 225 "-" "iOS/11.6.1 (20G224) remindd/1.0"
ipv4.macos - - [19/Dec/2021:21:53:04 +0100] "PROPFIND /calendar/dav/USERNAME/user/ HTTP/1.1" 405 225 "-" "iOS/11.6.1 (20G224) remindd/1.0"

when I enable the account on iOS I get:

ipv4.ios - - [19/Dec/2021:21:51:54 +0100] "PROPFIND /remote.php/dav/principals/users/USERNAME/ HTTP/1.1" 401 569 "-" "iOS/14.8.1 (18H107) remindd/1.0"
ipv4.ios - USERNAME [19/Dec/2021:21:51:54 +0100] "PROPFIND /remote.php/dav/principals/users/USERNAME/ HTTP/1.1" 207 537 "-" "iOS/14.8.1 (18H107) remindd/1.0"
ipv4.ios - USERNAME [19/Dec/2021:21:51:54 +0100] "OPTIONS /remote.php/dav/principals/users/USERNAME/ HTTP/1.1" 200 0 "-" "iOS/14.8.1 (18H107) remindd/1.0"
ipv4.ios - - [19/Dec/2021:21:51:54 +0100] "REPORT /remote.php/dav/principals/groups/ HTTP/1.1" 401 569 "-" "iOS/14.8.1 (18H107) remindd/1.0"
ipv4.ios - USERNAME [19/Dec/2021:21:51:55 +0100] "REPORT /remote.php/dav/principals/groups/ HTTP/1.1" 200 290 "-" "iOS/14.8.1 (18H107) remindd/1.0"
ipv4.ios - - [19/Dec/2021:21:51:55 +0100] "PROPFIND /remote.php/dav/calendars/USERNAME/ HTTP/1.1" 401 569 "-" "iOS/14.8.1 (18H107) remindd/1.0"
ipv4.ios - USERNAME [19/Dec/2021:21:51:55 +0100] "PROPFIND /remote.php/dav/calendars/USERNAME/ HTTP/1.1" 207 1428 "-" "iOS/14.8.1 (18H107) remindd/1.0"
ipv4.ios - USERNAME [19/Dec/2021:21:51:56 +0100] "PROPFIND /remote.php/dav/principals/users/USERNAME/ HTTP/1.1" 207 315 "-" "iOS/14.8.1 (18H107) remindd/1.0"
ipv4.ios - USERNAME [19/Dec/2021:21:51:57 +0100] "PROPFIND /remote.php/dav/calendars/USERNAME/personal/ HTTP/1.1" 207 295 "-" "iOS/14.8.1 (18H107) remindd/1.0"
ipv4.ios - USERNAME [19/Dec/2021:21:51:57 +0100] "PROPFIND /remote.php/dav/calendars/USERNAME/personal/ HTTP/1.1" 207 526 "-" "iOS/14.8.1 (18H107) remindd/1.0"
ipv4.ios - USERNAME [19/Dec/2021:21:51:57 +0100] "REPORT /remote.php/dav/calendars/USERNAME/personal/ HTTP/1.1" 207 2551 "-" "iOS/14.8.1 (18H107) remindd/1.0"