I too have been having pixelation problems that seem to come and go.
Specific channels on specific days and even down to specific hours.
I have changed equipment, check "cabling issues". all to no improvement.
I have been very suspicious of a home near me that has a very tall radio tower. Ham, shortwave whatever.
The timing of service pixelization is usually near sundown. And the channels effective show clear, then disruption for very non linear time segments. Like there is a conversation going on. Clear picture, then snowed under for 1 to 3 minutes, clear for several minutes then pixilation for 5-10 minutes. Then there is a clear channel reception for 30 to 40 minutes. It is so intermittent it is hard to think this is a cabling issue.
I know digital communications, I have worked in that industry for decades, The number of channels simultaneously being transmitted on the cable is complicated, but to only have 1-4 channels affected out of several hundred with this pixelation issue that appears and disappears is something that is failing in the devices along the Cox cable equipment or an outside disruption along very specific wavelengths that affect specific channels.
I'm beginning to rethink my subscription of services from Cox