@GreenSock Thank you for your answer and advices.
I managed to make scrollsmoother work with scrolltrigger, but impossible to reach the effect I want. What I want is that every box appear one after another, and set up the moment they arrived through the start position of the animation. But when I set up a start position, it remove/adds a margin or a padding somewhere. I'm sure I'm doing something wrong, but I can't figure it out.
I updated the demo to make it more simple: https://codepen.io/Achyl/pen/bGajrjj
And this is the effect I would like: https://drive.google.com/file/d/1EX00DgUhxdyyYL87ERtXG2AuYgoUo-X5/view?usp=sharing
It has been days I'm struggeling with that, I red all the doc I could. If you could help me with that it would be awesome !
Simon