Aimesh problem with AX68 and XD6

[sn2018]

I have an RT-AX68U with 3004.388.11 and created an AiMesh system with 2 XD6's. One XD6 is connected to the AX68 via cable, and one is via Wi-Fi; both XD6s have the latest firmware from ASUS. The wired XD6 works very well but not the WiFi one. When I set it up, things look good but the WiFi connection turns "weak" when I move it further away from the AX68. The WiFi XD6 is about 20 ft from the AX68 and about 40 ft from the wired XD6. It appears to be attempting to connect to the wired node rather than the router. Is it because the router has Merlin FW and the WiFi node has stock ASUS FW?

 

[degrub]

No. Merlin makes no difference .. The AiMess is ASUS code only, so you might as well just run factory. Did you create the node while it was close to the Main router ? If not factory reset it and join it to the main.
Otherwise, the Node is getting a weak signal from obstacles/interference or the MAIN is getting the same from that node.

Hardwire the node like you did the other.