AC66u - when the 2.4ghz Channel bandwidth is set for 20/40 it will be only channel 6, not possible to change.
But when I set the bandwidth to 20 or 40 the channel selection works as normal.
Tried with two browsers, same result.
Anymore places to look?
I think this has been posted half a dozen times already on these forums. The wireless driver is the one that establish which channel it uses when downgrading a 20/40 channel to 20 MHz. I have no control over it. Just set it to 20 Mhz (like you should be doing on the 2.4 GHz anyway) and it will properly use the channel you configure.