I can't find those channels anywhere on mine, only 100-140. Maybe it's only available in some countries or something? I am in UK.Hmmm...just noticed that the XT8's now have the UNII-4 channels, 165 - 177, or 5.9GHz with this new firmware.
I am puzzled by router.asus.com >Advanced Settings >System Log >Wireless Log
because it says backhaul channel bandwidth is "160M" despite I have "Enable 160MHz" Unticked in wireless settings, and an analyser app on mobile is only showing hidden 80Mhz. Is the wireless log buggy?