Login light problem - spins forever, but logged in when refreshing page

Hi guys,

Just made my installation of Nexcloud and got it set up on a pi4 with external hdd.
I’m using a docker installation and uses nginx-proxy and use of let’s encrypt
I’ve created admin-account and user accounts.
When I’m logging in with the credentials the screen just stays put and the login-ring spins forever. But if I refresh the page - I’m logged in.

Same happens on the phone-apps but there it’s not possible to refresh so to say.

Any ideas what I can do to get rid of this problem?

Tried to search but since I’m new to this and really trying to learn I don’t wont to try to fix an issue that might not be the right one.

Thanks in advance!