Login only works after page reload

I have this annoying issue that I cannot login into Nextcloud without a page reload in the browser. If I try to log in via browser nothing happens after I click on the log in button. If I reload the page the dashboard page opens and I’m logged in. Unfortunately this issue leads to the problem, that I cannot login via Nextcloud app on my phone. When I try to log in nothing happens and there’s no possibilty to reload the page. I assume that it would work if I clould reload the log in page.
The strange thing is the log in process worked flawlessly until a few days ago. I also updated my Nextcloud to the latest fpm-alpine Docker image but the issue remains.

Can anybody help me with this problem?

The solution of the problem was the same as in this thread: