Sorry for my non existing response, I somehow missed your post. The Issue is probably as @devvv4ever writes not nextcloud related. I changed for testing purposes my dav-Server to baïkal and katana (both are no longer maintained), still had the problem.
As written in my previous post, resetting my phone did help at first. A few days ago, I broke the camera of my old HTC 10 with LOS 14.1, time to move to my Nokia 6.1. Well, after setting everything up the issue is back
ICSdroid is also affected, interval is switching back to manual after a reboot.
I’d like to help troubleshooting this issue, what can I do?
P.S.: can I unmark this thread as solved?