I just bought this new router and it works fine but I do have a Dell gaming computer that is not able to read my wifi network, all other devices do read it but not this computer, what am I missing?
If its a single computer doing it, I'd look at the computer first. Check the drivers on the wifi adapter being used. Intel drivers are notorious for not functioning well with AX or 160hz.
The rax120 is using draft ax and 160hz channels. Some wifi adapter don't accept this because they're to old or drivers are to old. You can try disabling AX or setting the speed down (which moves you from 160 to 80hz)
here's the manual that shows you how to change these.
I wouldn't say Intel drivers are notoriuos with HT160, that isn't the case. As for AX yes some older Intel cards like the 7260ac need a driver update as they have issues with AX routers/APs. Most laptop manfacturers don't provide the latest OEM drivers and usually stop after a few updates, hence why I ussually reccomend people download drivers directly from the actual component manufacturers especially for WiFi and Graphics.
