Problems with groups since 20.0

Since I updated my nextcloud (hosting it myself on opensuse tumbleweed) I got some problems with groups-management. Since I run it in german, some translations might be off, but you will get what I mean.
In the “external storage” section (Where I can mount samba shares) there is a “availabe for” space. If I click there, it says searching for a few seconds and then nothing, I dont see the groups I should be able to add.
Or is I add the group “admin” to a user, I can not remove that user from the group admin, I can only delete the user.
Any suggestions other than a complete reset of the cloud?
Thank you

Stay relaxed and wait for the v20.0.1 release, in which the group problem should have been fixed.