Thanks for the replies, but I think you misunderstand. This is about the macOS companion app, not HA itself. The server is definitely up and running and fully accessible. I have other devices where the companion app is running perfectly on (macOS, iOS, and android devices). My server is also accessible through the web UI.
AFAIK, the companion app at this point should be fully installed when the .app file is in your Applications folder. That horizontal line seems to be like it’s some sort of overlay that’s not showing properly for some reason to me. It’s also very strange that the app just isn’t closable at all for some reason. That also makes me think something is being shown, or trying to be shown, but isn’t actually fully visible.
Does the above make sense?