Backgroundvideo changes backgroundcolor (Problem)

Hey Guys,

i Hope y‘all having a great day.
I have a problem with my backgroundvideo.
It’s an mp4 and created in aftereffects. I tried to use Lottie but bodymovin somehow couldn’t render it the right way, so I had to use mp4 and backgroundvideo.

The problem is that it’s somehow changes the backroundcolor of the video when it’s in preview mode. In the designer everything is the way it should be.
It has nothing to do with after effects, it seems to be a problem in Webflow.
I can’t share a read only link because it’s a client project and at the moment not public.

In the pictures attached you can see what I mean

Maybe someone already had that problem and could help me with it.

Thanks in foreward,
Jan