Dynamic wallpaper glitch (Big Sur, Quadro K600)

Hi guys,

Recently made some hackintoshes with DELL Optiplex 9010.
All of them work perfectly with Quadro K600 GPUs.

Only bug I have is that one, but couldn't find any information about it.
This glitch appears in Desktop (on one monitor only, an old Dell monitor) and on Login screen (on both). It only happens when using dynamic wallpapers, not fixed ones.

Glitch as seen on second screen

Do any of you have seen this glitch and have any clue how to fix it ?

Thank you very much everyone.
Have a great beginning of week.