"Unable to access Home Assistant" Error on external login

Hello, I recently began having issues with accessing my HA instance remotely. I am running Nginx via docker in an Unraid server separate from my HA instance which is on an RPI 4B. I have added the HTTP trusted proxies section to the configuration.yaml and there are no errors in the logs. When I access HA via my external domain I am able to login and get through the 2 factor, but I then get a page that says “Unable to connect to Home Assistant.” I have the correct domain set as the external URL in the HA configuration and all my other external sites are working fine. I have also added proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; to my Nginx config for the domain as well. The proxy is clearly working because I can get to HA but I can’t actually get to the UI once logged in.

Any suggestions of what to look at next?

Thank you.