Since installing Sonoma and doing all the updates, several Alpha channel videos, shown as Apple Pro 4444 with alpha, work OK, but tiny blocks of pixels appeaar on some files I downloaded from Envato

If I open it in Photoshop, or any Adobe program, or Apple motion, Quicktime etc, thy all show these bars, when shown as transparent the blocks are transparent, this i did a screen shot in a re rendered Motion file and it still plays incorrectly, this started with my new M3 iMac, and Sonoma, there is one video player whith it plays fime as transparebt but nothing else works, I have many alpha videos and most play fine if I read the file info it says Apple prorez 4444 with alpha. Any ideas I know it's missing a codex someeher but why will even the newest Adobe and Apple programs not work? A mystery I did update yesterday to the latest build and all Adobe are up to date too. In this still frame it appears as long blocks of pixels, my old computer played them fine and i freshly downloaded them again. Stumped.