Just bought AC1300 Archer T3U Nano and cannot find my iPhone network when it's in 5 GHz. 
It works when option "Maximize Compatibility" (2.4 GHz) is enabled. 
Tried with oldest drivers, and changing wireless mode to 802.11a/c and same problem...

I'm on Windows 11. Note that I can't choose channel on iPhone. I can't try with Android smartphone.