Hi Stephen,
Sorry, I dont' know what MBP stands for, but I looked up specs on "Ubiquiti EdgeRouterX"
that says they make passive and PoE models. On a far chance, if you happen to power your
AP from this device, and all the other ports too, could our AP be losing power from the ER-X
such that it's 5G radio blinks? Not sure, just an idea. Your AP support info logs might offer
some other insight into what's happened.