What’s your source? Satellite, cable, over-the-air, internet streaming?
If you’re getting pixels, it’s usually a transmission/reception issue. If satellite or over-the-air, it could be local weather or mis-alignment. If cable or streaming,then it’s likely an issue with the carrier. If streaming over the internet, reboot your modem and router.
Cable, and the NYC feed is breaking up and the Philly feed is "temporarily unavailable".