Hi, I'm trying to load a robot hand on Unity using Unity Plugin with URDF model. When I load the hand, it looks like below, and thumb joints are located like this. But when I click the play button, the most proximal joint of thumb rotate like below and get stuck. I guess it's because of the merged part of thumb link and the base link. Why does this happen? I attached the URDF. The problematic thumb link's names is 'finger_1_1' the most proximal thumb link. Thanks in advance.