Well this has been a strange set of events, suddenly one of our Unifi APs reports that it is in isolation mode. I had no idea what it was. The one report said that it was possible that the network cable was bad.
The symptom is that you reboot the AP and it looks OK, but then it loses connection and reports no internet access. From the other side, the controller reports that the AP is “Isolated”.
How often is this going to really work. Well, I swapped the cable and all is fine. Wow, I love the internet!