Did anyone ever get to the bottom of this?

I have exactly same issue and have just spent one hour to online VM help, including them taking over my desktop. They just deny this Virgin Media SSID exists, even though I show them WiFi analyser screenshots and that it is visible to both my Android & IOS home devices.

When I select on Android, I get asked for Phase 2 Authentication - EAP certificate?

PS: I see your Cable Modem is ARRIS, mine is NETGEAR, so it's clearly not tied to one vendor

It does not seem to affect performance, but like you I don't like the idea of an SSID broadcasting from my home without my control.

I asked for it to be logged with third line support but they woudn't