Thanks for the reply 🙂
I actually fixed it : I still don’t know why, but for some reasons the colorista III plug-in made this happen. I just deleted the effect layer that was on these clips and it completely fixed the render issue… So I had to find another way to color grade thèse shots, which was pretty annoying, but well, if this problem ever happends to anyone, this might help 🙂
Cheers