Chromecast Ultra connected but no internet?

I returned my first one and the second one does the exact same thing. I can connect to my Xfinity Xfi network but the Chromecast states it has no internet. Funny thing was after many resets and setups I got it to work once and by the next day it stopped. That was the first one. I have an old 1st Gen Chromecast that works fine. I have:
-Reset my modem/router.
-Reset the Chromecast
-Used combined 2.4 and 5Ghz networks
-Tried it both connected to my receiver and Television.

Any thoughts or settings I can use.

Thanks!