Figured it out. Comcast used the wrong MAC address to setup the modem. I told them there was "WAN MAC" and "HFC MAC" on the bottom and they asked me for the WAN MAC, which is wrong - they should have...

This AP was working fine. I swapped out one modem for another, then returned the new modem and put the old modem back. The EAP650 was connected without issue previously and also worked on the new...