Humanoid animation created in Maya has incorrect Thumb rotation when brought into Unity.

Hi, I have an animation created in Maya which holds an object. While holding the object, the thumb of the hand is closed appropriately enough to hold the object. However, when the same
animation is brought into Unity, the thumb finger is wide open, while all other fingers are folded appropriately.

I have tried adjusting the Thumb finger Stretch and Spread values in Muscles and Settings tab while configuring the avatar, but of no use.

Go back to Maya and check the Bone Roll on your rig for the thumb bones. Align along z (I Imagine) for the direction of movement.

Or could be an ‘unapplied’ Rotation.