Pretty much all the channels in the 500s are affected. USA is the worst, which is by far my favorite channel. Unwatchable half the time.
Called supports many times. Same thing every time, they tell me to unplug every single unit in the house, coax and power. Then hook them all back up. I've done this at least a dozen times, works for about 30-60 minutes. Have been sent new DVRs, does not fix it.
Susanlynn9, used to have similar issues. Check for any loose connections to your set top boxes/DVR, and check for any small splits with the coaxel wiring. I had a tech come out and he had to replace the wiring on the back of my home which solved this problem. Good luck!