3dmax biped prop would shake in unity,3Dmax use Biped prop Position and Rotation Space to World,but it shaked when export into Untiy

Hello, guys
I have a problem with the 3DMAX Biped Prop. I used Prop to key the weapons animation, and it linked to hand but it Position and Rotation Space to World. In 3DMax, the animation was right, but when it exported to Unity, the prop animation would shake. How could I deal with it?
Thank you very much!
The left one is in max, the right one is in Unity, same frame, but different position.

And I’ve checked the fbx file in MotionBuilder, the prop’s animation was right.