Every other 4K blu-ray title pixelating

[pow]

Has anyone else had this problem?
I have a Panasonic 820 4K blu-ray player and recently just about every other title i purchase seems to have problems playing. Either immediately when the film starts or after 5-10 mins the picture starts pixelating to the point where it locks up the player.
I've replaced the HDMI cable, cleaned the disc surface and reset the player to factory defaults and nothing corrects it.
I even purchased a second panasonic 820 player as had read that the players sold during covid had cheap components as parts from Japan couldn't be sourced, but the newer player is almost as bad (if not worse) that the first one.
Any advice, info or knowing that others have the same issue would be very helpful, as I'm now getting to the point where I'm starting to tear my hair out in frustration!!!

For ref, the pixelating happens on the following discs (among others):
Black Phone (UK, Universal release)
Red Eye (UK, Paramount Release)
Kiss The Girls (USA, Paramount Release)
Guardians of the Galaxy 3 (Disney, Australia Release)
Cocaine Bear (USA, Universal Release)
The Lost City (UK, Paramount Release)

[-JKR-]

There might be something wrong with your 4K player.

[ronboster]

Sorry for your issues, but this is the wrong forum. Here's the owner's thread for your player:

https://forum.blu-ray.com/showthread.php?t=305030

[pow]

Managed to get to the bottom of it. I've just bought two HDMI-certified 2.1 cables and after connecting 4k player to TV and TV to soundbar with them, all discs now seem to play fine. Other cables said 8k so should have been ok, but the Anker ones i've just bought seem to be the only ones that are certified by HDMI forum.