Avastar : Alter to rest pose

Hi, i followed that tutorial :

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But when i hit bind to armature, my mesh clothe get deformed.
I made a quick video to show you :

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I created the pants with Marvelous Designer with the A pose you can see on the video.

On the tutorial we can see on the first video, she doesn't have that deformation after binding...
Maybe i have to change some properties to the lara mesh body first ?

Any idea ?