server.eosdash_host defaults to 127.0.0.1 (not None), so the fallback in run_eos() that inherits server.host never triggers. The --host 0.0.0.0 CLI argument only sets server.host. As a result EOSdash binds to 127.0.0.1 inside the container and the Home Assistant Supervisor ingress (ingress_port 8504) cannot reach it (502). Set EOS_SERVER__EOSDASH_HOST=0.0.0.0 in the image.