Nextcloud ics calendar import problem

Import ics file to an existing calendar not possible. The calendar import dialog forces import into new calendar. (popup dialog does not display available calendars, or intermittently displays a subset of available calendars). Reproducible in Firefox and Chrome, also after disconnect and reconnect, after cache and cookie flush and after browser restart. Issue occuring in Nextcloud 20.0.4 and 20.0.7 with calendar app 2.1.3. Anyone else seen this or have an idea how to workaround or fix ? Thanks

I also realised this right now with Nextcloud 20.0.7.
It was not like this before version 20. Might have to check in Github also, seems to be a known bug Issues · nextcloud/calendar · GitHub