Redirects user to the wrong port

[haloflooder]

I installed PHPBB with the bitnami phpbb docker image. It's also behind a reverse proxy using nginx since we have other services on the server as well.

When using the social login extension and a user is redirected after the oauth is completed. It would redirect the user to something like https://forum.example.com:8080/blahblahblah instead of https://forum.example.com/blahblahblah since the internal webserver from the docker image is using port 8080.

Is there a way to change the redirected url so it doesn't include the port?