Nextcloud redirects to localhost:881

So I installed the linuxserver/nextcloud image as well as the linuxserver/mariadb image and set them up.

Now this works fine as long as I am in my local network and access my home server via his internal IP-Adress but as soon as I try to connect to it via my domain it redirects me to localhost:881.

I have setup a nginx proxy to redirect to

EDIT: Note that I forwarded the docker Port from 444 external to 443 internal.

please review reverse proxy settings. Likely you misconfigured some overwrite parameter. use search the issue was discussed often already.