Nextcloud Calendar reminders on Android phone

Hi folks,

It can be that this is more like an Android “issue” than a Nextcloud, but I’m trying to figure it out for weeks now and no success:
I’m syncing an android phone with Nextcloud calendar. I’m the admin on the server and I’m creating calendars what is shared with other users on the server. The users syncing their Nextcloud Calendar with their Android phones using the NC mobile app and DAVx.
All fine except one issue: Whatever settings we try in Davx and the Android Calendar app the reminders set up in the NC Calendar for an event are not going through (or not picked up ) by the android calendar: f.e if I set up an event in NC and set a reminder 60 min up-front, I cannot get Android Calendar to take over the 60 min up-front reminder. The only thing I can set up in Android is the standard reminder what is the same for each event.
I have an IOS phone and with the Iphone the same is working fine, the Iphone calendar takes over the reminders set up in NC and drops the notifications as it is set on the NC server.
The android calendar behaves just like the reminder parameter was not received…
Thanks for the tips in advance,