I do have a Nucleus rev A, but in another location with a different IP address.
We discovered that it was related to StarLink. There was another member (Profile - Scott_Muckleroy - Roon Labs Community) located 50 miles or so from my place who also used StarLink. The best guess is that we were both being served by the same ground station and somehow his configuration was advertised to my Roon Core.
I disabled UPNP on my Unifi router/firewall and rebooted the StarLink router. After that, I stopped seeing the messages. But I’m not sure if that’s simply because I was now being served by a different ground station.
Please contact Scott if you would as he was concerned that Roon was somehow advertising his configuration to the broader Internet. It’s not clear I could actually get to his setup since all I saw were inaccessible private IP’s.
—Dave