@rfc2822
Thanks for quick reply.
All required setting should be done, same as for other apps with similar requirements (I know some more). And even after new installation (which requires settings to be done again) it worked. Also contacts should be affected not only calendar entries.
And … doesn’t that only affect background sync and manual sync should work? I’m using the app for some months now and did not had issue before. But then even keeping mobile on, doing changes there and starting manual sync did not sync calendar entries to NC.
@tomcat-x Did you have a look at the DAVx5 / adb logs? Is there anything interesting when you start synchronization?
At the moment, we get more reports about different vendors’ Androids not starting sync anymore. Probably the next generation of battery saving…
@rfc2822
At the moment it is working with 3.3.7, so I think there would be nothing in logs. I don’t want to change but couldl try to backup current working version with Titanium and then update to 3.3.8 again.
Or do you think it will also happen with 3.3.7 and I just have to wait?
@tomcat-x said in Sync with Nextcloud Calender Stopped (after some runs?) with Rel. 3.3.8:
Or do you think it will also happen with 3.3.7 and I just have to wait?
Unfortunately yes…
@rfc2822
Did not happen, even after a week. But as promised I did backup and update to 3.3.8 again. So far it is still working. No idea what happened. As re-installing of 3.3.8 did not help but downgrade to 3.3.7 did, I was sure it has to do with version.
@tomcat-x In 3.3.9-beta3 we have introduced a “foreground service” with permanent notification, which may help when the operating system doesn’t allow the app to start anymore.
Do you have the Google Play version?
@rfc2822
No, I’m using F-Droid where possible.
But anyway I think for me it is fixed now. Maybe some “bad coincidences” 
@tomcat-x By the way, which device / firmware do you have?
@rfc2822 It is a Samsung Galaxy S20 5G (exynos) and Android 10.
New thread: https://forums.bitfire.at/post/14019