Question about cable TV signal breaking up 1-4 PM in 22180 zip code

Between 1 pm and 4 pm EST in zip code 22180 (Vienna, VA) that cable TV signal (basic cable) will show pixels and break up, and the sound becomes distorted as if beeping, every day.  Cox technicians have come out and installed an amplifier but to no avail.  I will have them come out again.

I wonder if other people have observed this phenomena.  It only happens between 1-4 pm, not in the morning nor evening, and I think it's related to something Cox is doing upstream.  Several years ago a technician came out and replaced a bandwidth filter of sorts used to block premium channels, by climbing the telephone pole to get to the filter, and I wonder if there's another similar filter that's at issue.  But since the distortion happens between 1-4PM, maybe it's in the Cox transmission center?  Or can higher temperatures in the afternoon trigger something?

Any advice appreciated.