Is my ROCK server hosed? How to fix?

I’m running ROCK on an Intel NUC. Until a few hours ago, everything worked great. I used Roon this morning. When I tried to run it tonight, I got the screen asking me to connect to the Roon Core after which I go the screen asking for my UserID and password. I know these and entered them. But that only took me to the previous connect screen in an endless loop between the two screens. But the ROCK server is showing up with Green status, so the Roon app can see it, just not log in. I am able to ping the server but I an not able to access the built-in web page at the same IP address. I’ve rebooted the server multiple times, but that doesn’t fix anything. What do I do now?

Attach the ROCK server via HDMI to a screen and keyboard, boot it and see what it says.

Additionally: Posting screenshot/photos of what you see would be a tremendous help for helpers.