I'm getting a white screen except during commmercials???`

This is very strange.  On one of my computers, I get a white screen when I'm watching programs but it goes away during commercials!?  This only happens on one of my computers.  I'm using Chrome on both computers.  I've tried other browsers on the computer where I'm getting the white screen, and I still get the white screen.  I called Xfinity yesterday, and they couldn't resolve this.  Hopefully you can.