Freezing Channels while watching cable TV

Over the past couple of weeks, I've noticed that certain stations freeze while watching cable tv. The two of note are ABC and CBS. ABC is the worst. It happens at various times of the day. The screen locks up for a minute or so then it unlocks and goes on as normal. There are no messages and nothing else was taking place - no channel changing etc. This happens on multiple TV's so it's not one in particular.

This happend "a while ago" and I got in touch with you guys. You all did something and it stopped for quite a while. Not sure what's going on but I could use some help. Just a note - watching TV now and ABC just froze for about 10 seconds.