Looks like it's a thing: https://forums.xfinity.com/conversations/x1/pixelation-on-sports-channels/634d16af2ff2c66589010ac4Not sure why, but I get a lot of pixelation and freezing up on ESPN football on Xfinity. I've noticed this behavior on ESPN for a couple years. It's annoying. No other channels do this.
Roll Tide!