WIFI bug of the nighthawk M1

Something I noticed last night with the Wifi . My android phone connected to the M1 Wifi and both phone and my pc (pc being connected via a switch connected to the M1 ethernet port) could network across the Wifi. The issue being that the phone would timeout trying to access anything on the internet. Things I tried to resolve this :- I turned the phone on and off. I turned the M1 on and off. I finally turned Dual band back on in Wifi ( I previously only had 2.4 ghz enabled before) and then I was able to access the internet as normal. Also I had just enabled Wifi range to long just prior to this issue