The manny hand is attached to the motion controller and the provided pose for the motion controller in hand tracking mode is not the same as the hand trackings actual location. You would want to adjust the meshes actual relative offset to the motion controller, or manually position the mesh to the hand tracking information by setting its world location.
I really don’t get why they didn’t standardize hand tracking to their “universal tracking root” when tacking the extension on and passing the pose out but it is what it is for now.
You can ditch the grasping hand all together and just use a raw mesh with the OpenXRHandPoseComponent to drive them in the same BP if you want, the grasping hand does a lot of extra things.