Nighthawk m1100, Net cuts off only on movie streaming.

I have this router got it on april 20th from a broadband company. I can play games on my xbox, i can stream movies on my cell phone, i can play games from my PC as well. The issue comes on my PC or my xbox when i try to stream movies there it losses net connection and makes me reset the router every 20 to 30 mins. When gaming it doesn't need rebooting.I have done things i read about such as set the Cellular band region to LTE All, Put network mode on manual and locked it to AT&T, Disabled WiFi Standby. We have tested running nothing but the xbox or PC alone on the system movies still shut down. Oh and it streams music just fine as well. Please help me and my family are tired of watching movies by connecting a cell phone to the TV. 

(OH JUST A NOTE: Before mentioned. It does not let me select device in the status and under administration i only have password change no other options about firmware so no idea what firmware i am using.)