Login android app server address with port specification

My new Fritzbox 7590ax does not release port 443 to Raspberry with NC. I have changed the port in Nginx to 61000. I can log in with mydomain.org:61000 in the browser, but not in the app. Error: Host not found. Does anyone have a solution? Thank you very much.

With kind regards


The reason is not clear to me, but it works now.
I had also changed the DynDNS service. After uninstalling the Nextcloud app, restarting the smartphone and reinstalling the app, I was able to log in with my server with port specification.
It had worked immediately on my iPhone.