White dots around transparant layer - premiere

[hskb]

Hello,

Im encountering a problem which i cant seem to solve myself.
As shown in the image premiere is rendering in some white artefacts around the edges of an alpha layer. It shows it in the preview monitor aswell as in the final export.
Emptying the cache wont get rid of the problem, neither does re-importing the .mov file.

Extra info:
- The white dots seem to be less severe in screenshots, but the problem is way more apparent in the final export.

- Sequence is UHD

- Export is HD

I hope someone can help me with this problem.

[hskb]

Quick side note, if I re-export the mov. file with alpha layer, the dots dissapear for a while. But they always seem to return after a while.