I am not sure which setting works. But doing the steps above seem to make my WiFi AC devices connect to 5ghz more. Especially my redmi smartphone which always connects at 2.4ghz previously now connects to the 5ghz more.
I kept the WiFi agile option on
This is because the 2.4ghz radio starts first or something after applying changes . The 5ghz takes a while to show up. The client connects to the first available band
My take is that the smartconnect which is. Asus feature and WiFi agile multi and may be conflicting with each other. So disable smart connect and separating the ssids works better
Disable roaming assistant for 2.4 GHz
-90 for roaming assistant under 5ghz
Try these values. If they are not satisfactory, disable smart connect and use 2 separate ssids.
Well I've separated the bands and under 5hz roaming assistant, put in a value of -90 and disabled 2.4 ghz roaming assistant. Now my AC devices connect to 5hz often compared to previously( under smartconnect single ssids ) where they would connect 2.4 GHz most of the time.
I am not sure which...