XT8 mesh: second node synchronising

[thegios]

Have an XT8 with two nodes: one connected to the router, second connected via WiFi back haul to first one.

Recently second node has started going offline with led blinking in blu. Only way to solve is to turn off NOTH nodes (turning off second one is not enough).
Any reason why this would happen.
Nothing has changed in 3 years.
Thx

 

[degrub]

Outside wifi interference is possible. Radios/power supplies do age, particularly if in noisy AC power area. Lightning strikes nearby can also wear them down or kill. Check signal strength/quality where the second node is located ( you will have to power it down to get a reasonable read with an app , preferably on a laptop with a good AX receiver (2x2) and not a phone ( unless equal)). On the bands used to connect the two nodes and the main router ( 2.4GHz, 5GHz, 6 Ghz - if applicable) , look for 1) RSSI value from the other node and the main router , 2) look for similar RSSI from outside sources (anything within 5-10 dB can be an issue).

Check how warm/cold the power supply bricks are for the units - cold/warm/hot to touch.

Are the nodes on UPS or at least surge arrest plug bars ?