When I upgraded my smart phones recently to Android 7.0 I started to experience WiFi issues. The phones would constantly disconnect and then try to reconnect to the network. The other devices on my network seemed fine which indicated the problem likely was with the Android 7.0 build considering the phones were fine before the 7.0 upgrade.
After a few days of looking online and adjusting settings on the phones I was quickly realizing it was time for Wire Shark. After grabbing some packet captures I started looking through the TCP stream and was able to trace the issue.
After reviewing the WMM protocol logic and looking at the TCP stream it seems that Android 7.0 doesn’t handle the power save station (STA) triggers correctly which causes a reset.
I disabled WMM on the router and the problem was solved. In theory disabling WMM should slow traffic but not enough to be noticed.