Resync all Records in Nextcloud Database, why?

Operating system

Linux

Joplin version

3.1.24

Desktop version info

Joplin 3.1.24 (prod, linux)
Client-ID: 07709277fbd244c2a291879e8a4ed5a2
Sync-Version: 3
Profil-Version: 47
Unterstützter Schlüsselbund: Nein
Revision: d581264
Backup: 1.4.2
Diff view: 0.1.1
Victor: 1.0.3

Sync target

Nextcloud

What issue do you have?

Due to an error in accessing Nextcloud, I was unable to access the Joplin database hosted there for a few days.
After I restored access to Nextcloud* and tried to synchronize Joplin, I realized that the synchronization takes a very long time and seems to affect all records. However, I have not changed any records in the Joplin client and the database in Nextcloud has not been changed either.
Why are all records being resynchronized even if nothing changed?
Is there any way to get around this?

*) selfhosted NC on Ubuntu Server, https://myipathome/remote.php/dav/files/user/joplin/

Is it uploading or downloading data? Maybe something off with the clock on the Nextcloud server?

It is uploading data.

The RTC time on the Nextcloud server was correctly set to UTC, the time zone was also set to UTC and not to Europe/Berlin as set in php.ini.
I have now changed the time zone with timedatectl set-timezone.
I will try to synchronize again after a restart.