Two rigidbodies hit

Hi I am trying to learn Unity Multiplayer and until now I didnt have problems.
Now my problem is with two rigidbodies when they hit eachother. The rigidbody which gets hit doesn't move at all no matter how fast and strong i hit it with another body.

When i run the same scenario offline (without multiplayer network functionality) my rigidbody moves after being hit.

What am i missing in the multiplayer network part?