I have: AXE16000 primary node; AXE11000, RT-AX86U, RP-AX56, and RT-AC68U nodes. The RP-AX56 is connected to a wall outlet and died immediately when the power went out. The rest have UPS/battery backup. The RT-AC68U went down first. (The battery must be weak). The AXE11000 went down next. The AXE16000 and RT-AX86U were still on when we left the house. When we came back the power was back on. The AXE16000 and RT-AC68U reestablished uplink. The AXE11000, RT-AX86U, and RP-AX56 I needed to disconnect, move to nearby the AXE16000, perform hard reset, then add back to the AiMesh. This was quite tedious, and the AXE11000 refuses to connect via 2.5 G ethernet, only via 1 G WAN port (ethernet backhaul). Prior to the power outage a long while back it was connected by 2.5 G ethernet backhaul to the AXE16000. Just before the outage for the past couple of weeks it was connected via 6 GHz backhaul (Auto backhaul preference, automatically switched).
The reason for the power outage was a nearby pole upgrade. I hope our power is more stable, it took a long time to repair my AiMesh network, (and I lost the 2.5 G backhaul connection that used to work on the AXE11000 node).