Roon air wifi connection problem

[Drifter]

What is your dBm with Asus?

As I run DOS and the latest version of the firmware, I think the wifi strength indicator is different to what you have (if I recall the non CI amps are still on old firmware).
If I cycle through the setup screens my wifi strength bars are at 100%.
My router is about 10 meters from Devialet (in a different room) and there is a significant brick and mortar wall between the router and amp. 
I have no issues streaming wifi over Air.