Change of User Quota not working

If I set User Quota to anything different Value like unlimited or default or 10GB it restored to 5 GB after some seconds.
What can i do?
I have latest Ubuntu LTS and latest Nexcloud version.
Thanks in advanced

Is there noone how can help with that?

I have the same issue, I am assuming I have a permissions problem but not sure.

what happens, could you make a short video or .gif that shows the problem?