Hi @Tu6Rob , I can help the first problem. By default we don’t ignore the collision for XRGrabInteractable GameObject so when it is grabbed by the player, it can collide with any colliders on the player, especially when during the locomotion. I assume your player GameObject has a collider like a capsule collider or the CharacterController component on it.
There are two ways you can avoid that unintended collision. One is to add the XRGrabInteractable to a layer which does not intersect with the player until released from the player’s grip. Another potential solution is to use Physics.IgnoreCollison to exclude colliders from hitting the player’s collider. I discussed this issue with more details in earlier forum posts. You might want to take a look:
For your second problem I don’t have a clear idea on which component went invisible and the setup, so if you can share more information we can dig more to it. It may also have to do with exporting and importing the 3D model.