@rfc2822 turns out there is a setting in the privacy guard to restrict app from modifying the calendar. And the calendar storage app had no permission to do so I probably took the permission, or maybe it was never set. Not sure

@6042114fa0 I have found emails where this was reported ... but very rarely.

I have the same problem with smartphone Leagoo Elite 5. It's work with caldav sync adapter but not with davdroid.

Hi all, first impression after last update to 1.5.01 is, that it is fixed now. I will continue testing next days an let you know, if i will face new problems... Thanks a lot for your support!