Are you talking about TV reception with a cable box or streaming video from the internet with a modem ?
I moved this concern here to the proper help board.
I am talking about TV reception with cable box. X1 cable box. The same channels pixelate.
when you are having the problem use a smart device (phone/tablet/desk or laptop PC) and check the stream version of the channel. do you see the same issue on that device? if not, then you have low signal, high noise, or both. check the cable ends on the coax on that set top box. are they tight? if so, a tech will be required to fix the signal issues (may be outside the home or inside).