Recent 8/11/26 firmware update bricked my Xfinity WiFi extenders

Worked on this for more than 12 hours.  Woke up.  Gateway was down.   Xfinity app required unplug of gateway and restart.   The WiFi extenders behaved strangely - blinking and cycling with connected status in the app while constantly blinking and occasionally going offline in the app.  No amount of power cycling the gateway or extenders and removing and reactivating them resulted in  connection with the lack of blinking.  Over the day, every troubleshooting method was deployed.  3 chats.  1 live call.   We swapped the gateway and now none of the extenders will even go online after removing and reactivating.