But after the comment from @marsara9@lemmy.world I changed it to pull the image from dockerhub instead of building it myself. Now it pulls correctly and the server comes online but is almost unusable. The homepage displays but I cannot login as admin or create a new user :/
Also, @hyper@lemmy.ml, what does your nginx.conf look like? Now that the webpage is loading, the backend might be blocked/not configured properly in nginx, so nginx isn't properly forwarding requests to the backend.