I finally find a way!!! i try different optios because i didn’t have the budget to buy new hard drives like thunderbolts… so I make differents trys the one that work was to make a sequence with all the cams(already sync) one after other then exported as Proxy in just one long archive, then take it back and cut each camara and each song then sync then the new multiclip run the cams flowly, I also put the proxy archive(like 200 g) alone in a 1T hard drive!