Nighthawk m1

Can anyone else confirm that the nighthawk m1 is locked its 5Ghz wifi to 64QAM modulation? Only allowing a max of 36mbps throughput? Mines an att version and can't seem to get past 60mbps max some times but will go way over 120mbps over ethernet. Going to test my brothers mr1100 tomorrow to see if all us versions are locked through the wifi. Easiest way is to enter the device info mode on a android phone with the number *#0011# in the dialer and click the 3 dots and enter the section "WIFI"