ItsMeDude
Occasional Visitor
Just bought a brand new RT-AX88U. Got through the initial setup and immediately upgraded to Merlin 384.9_0. Didn’t change any of the settings but was trying to find the 5 ghz WiFi on several devices that definitely support 5 ghz. Although the router indicated it was broadcasting, no device could see it. I factory reset the router and tried again, still no 5 ghz. I switched over to the Asus firmware 3.0.0.4.384.5640. 5 ghz immediately started working. Must be some sort of bug in Merlin. Thought posting here would help bring it to the attention of Eric. Should be easy to replicate considering it was factory setup without any changes to the settings on the Merlin firmware.
I had the same issue when I first upgraded. If I manually set the 5ghz channel to 161 or lower everything works fine. That's even with the AX framework enabled. If I set it to 165 it will disappear. I'm guessing that on auto that it's setting it to 165 because it's completely vacant of other APs. I scanned the channels and just forced them to the least used on both bands. I uploaded a screen shot. With it set like this it has been rock solid. I'm on 384.11.2
I hope this helps!