Having some trouble with my internet connection through wifi. N600 Router is what I have I believe.

I've been having some trouble with my internet connection recently through my wireless router. I get the little yellow triangle off and on with the connection at different times and I can't call my local internet provider because it's always working when they're open and then it quits when they're closed. I recently bought a Google Chromecast and some think it might be interfering with the connection but I don't see how. When I reset the router and cable modem by unplugging and plugging them back in they get the connection back sometimes but it's annoying not knowing when it's going to go out again and then come back. A few months before the connection would go out occasionally but not a few times a day. If you need any further information like IP DNS type stuff I can get it. I also recently updated the Netgear firmware if that makes any difference. Thanks!