Not sure how wired backhoul is being impacted by disconnects however. Its weird as hell. Have had good luck with the firmwares to be fair until the 388 versions
Just registered on the forums to confirm too, I have 3 XT8s with 2 wired backhaul APs. With the 388 firmware it randomly disconnects and reconnects with the red LED. It's only the wireless, anything connected directly to the nodes with an Ethernet cable are connected and reachable just fine