So I did some research (quickly on google ????) about video with transparent background thinking that doesn’t exist, but it does. So I finally render my composition in AE that was working. It’s a workaround for now.
Ahah I didn’t know I could clean the cache, weirdly it was set to only take 46go but it was 88Go on my poor 500Go ssd of my Macbook Pro. I’m happy I clean it for storage purpose, BUT it didn’t solve my initial issue.
Thanks for your answer, but I can’t use a render because on another composition not showing in the screenshots, I need transparency over my video in Premiere.
But I’ll try the two other things you suggest.