Pixelation on all tv channels

Recently having pixelation issue on all tv channels. Local channels are worse but all tv channels have the issue. Both my dvr box and my non-dvr box have the issue. Boxes are in different rooms on different coax jacks. No splitters. Have checked tightened all connections, replaced HDMI’s, rebooted boxes and refreshed. Same issue persists.  The Xfinity internet apps like Netflix and Prime are fine!  Based on this, possible suspect a bad connection or weak signal outside building or at street location. Can someone (support/technician) please investigate this?  ThankYou