iTunes breaks internet?

I have a Nighthawk R7000 that I've had for over a year and recently I constantly lose internet in a bizarre way.  I'll be streaming a movie and it keeps working, If I'm downloading a large file it still downloads, but any browser on the same PC will not be able to open websites and other devices can't connect at all and if I try to change to something different on the TV that is still streaming it will show no connectuon and not be able to stream anything.

I need to unplug the router and reset then it works again.

This sounds crazy, but I think by process of elimination of other things that opening iTunes on a PC is what causes the problem.  Does iTunes somehow change a router setting?  If so what can I change in the settings on either iTunes or the router to fix this?  I don't use iTunes for a server to share music between devices all I need it for is to manage the music files on my PC and copy them to my iPhone or iPad.

And if it isn't iTunes any other ideas what coudl be causing it?  I thought at first it was the iPHone but I turned off WiFi on it and kept it off the network for a couple days the probelms still happened.