Multiclip sync bug

FCPX is the best editing platform so far. As a producer, it speeds up my work. But today, I had an issue with multiclip function.

I always use this feature to synchronize 3 cam in a perfect studio environment.

I understand correctly the dialogue box options.

Bug:

Today, the function seems to no longer work at all. When the syncronizing dialogue box starts, it takes a sec to disapear as soon and the new multicam clip is not in sync.

This is a new bug that I've never seen before.

I've trashed the pref file, the problem still.

*** Important note***

The same footage is syncronizing perfectly on another computer.