Issue when sharing a project : sound track is crashing but preview works well

hello team,

I did purchase the last version of iMovie.

When exporting a project (let's say sharing it for iTune, for instance) I get some issues with the audio tracks linked to the imported video file.

The video soundtrack is available during the preview (sound is correct) but crashes at exportation (running the exported file in Cinema or even itune gives the very same results).

The video sound is then a long noise.... 'chhhhhhhhh'

Any idea will be very welcome.

Many thanks,

C.