Nighthawk AC1750 R6700 v3 : high latency when other devices used

[vorge]

Had this router Since November last year and everything has been great. Diablo came out and the first few days were fine, ping was always 40-70. 3 days later my girlfriend starts watching a show in the other room on netflix and my ping spikes to the thousands. Eventually disconnecting me. The streams I have on my other monitor, same computer start to buffer. I never lose internet but the connection just plummets. I know this after some time troubleshooting which simply involved her turning on any streaming service and starting to watch something. Her connection is perfectly fine but mine sinks. I'm on a wired connection and the tv is on wireless. This setup has been the exact same since the day the router came and up to right now. Nothing new has been added hardware, driver or firmware. When I speed test during these spikes it still shows the exact speed I should have and do have when nothing in the house is using internet besides this wired PC.

V1.0.4.128_10.0.104 is current firmware