DVR playback tiling and breaking up

A couple months now, every time i watch a recorded show, it gets pixelated and glitchy. I've had 3 technicians to my house to try and fix the issue, and 2 new cable boxes, but still having the same problem. I don't have anymore patience for this. I pay lots of money for this service and i think I'm going to lose my mind if i don't cancel this service. This is my final attempt..... Going to the forums😔🙄