I am now on 386.5_2 on a RT-AX86s and everything is super stable. Thanks, I had a lot of WiFi connection issues with 388.1.Nope - the problem is specific to the WiFi drivers provided for the RT-AX86U within the Asus stock code used to compile 388.1
This is closed source stuff which RMerlin can't fix - so 386.5_2 works so well on the RT-AX86U because of the stability of the stock driver it included.