Today I just flash AX3000 (AiMesh Router) from 3.0.0.4.388_23924-g23eb4d0 to 3.0.0.4.388_23925-g269b2a6. My RT-AC88U (AiMesh Node) firmware ( 3.0.0.4.386_48260-gd4c241c) loses the 5Ghz Backhaul intermittently. No matter how many time i reboot the RT-AC88U, it will still lose connection to AX3000. I re-flash back AX3000 to 3.0.0.4.388_23924-g23eb4d0, all problem resolved. Think there are some issues with the firmware 3.0.0.4.388_23925-g269b2a6.