Animation scaling wrong when importing into Unity

Hi,

I have several characters that have animations scaling problem after importing into Unity. They are rigged and animated in Maya, and the exported fbx also looks good when re-importing into maya, but the scaling looks wrong in Unity. For example, the following picture, the scaling looks correct when the pose is close to binding pose, but when something scaled down, it's kind of shrinked twice or three times than it should be.


The animation keys are baked to skeleton every frame. The Resample Curves is off and Compression is off.
I tried to exporting the animation in different ways like change all tangents in animation curves into linear, exporting the animation with the mesh or separate them, but all the results are the same.
I also tried detach the skin and delete history, then rebind, but still the scale looks correct in Maya, not in the engine.

Any other points that I should look into? Any info helps, thanks! Or any other debug aspects?