Tiling pixelation loss of sound

So yes.sound comes back. The sound and picture is fine for a period of time , then I lose sound for a second or two and then pixelation/tiling happens and then the picture cones back. Strange and weird 

In the past techs have changed all wiring outside and internally.  They tell me that Xfinity has a lost signal coming from the lines. 

They have found the posts outside have had corrosion at the taps on the lines 

@rgguzzi Does it happen during the commercials as well?

Have not seen that during commercials