Xfinity Gateway won't connect to Peplink Balance One Core in Bridge Mode

Another maddening issue with comcast. I have been using comcast cable and a separate AT&T line as my redundant connection. I recently downgraded to 800MPS on the comcast line because it wasn’t needed and shortly afterwards, my comcast gateway stopped connecting with my Peplink Balance One Core. Just keeps spinning and says connecting. This worked great for a year without any issues. after much trouble shooting, I thought the gateway went bad, so I got a new one. Same issue. It will only connect if I take it out of bridge mode, so now in the dashboard the ip address is 10.0.0.xxx instead of the external ip address. I have tried disconnecting all devices from the network, and changing the lan ip, with no success. I have switched WAN ports on the peplink and switched to a different ethernet cable. It’s definitely a communication issue between the comcast box and the peplink. Leaving it out of bridge mode will cause issues I am sure…

Any suggestions would be appreciated.

Thanks!

Here is the solution