I use Calendar on different platforms (Android, Windows, iOS) with CalDav.
In general, this works as well.
However, the synchronization takes several seconds (7s-30s depending on the platform).
The behavior with an empty and filled calendar is the same.
I have already looked around and searched for solutions such as deleting the AccessTokens, but nothing has helped.
Do you have any idea how to fix this?
This might be the same issue than this one (sync tokens are removed too aggressively).
I don’t have the problem that I miss data, but that the general synchronization takes quite a long time.
Sync tokens are used to accelerate the synchronisation (by telling if something changed rather than check every collection for changes).