RT-ac86u Aimesh node, keep disconnecting

[Chattanon]

Hi !!

I have problem with my rt-ac86u ,, currently I have 2 rt-ac86u,, one as a router,, and another as a aimesh node,,, I found that rt-ac86u keep disconnecting .
I tried the latest firmware and it's still the same
It used to work perfectly and smoothly ,,
any one having the same problem,, and what to do ?

please help me,
thanks
best regards

Chattanon