UNET ReplacePlayerForConnection problem

SOLVED:

Hey guys, I am from Germany so I am sorry for my bad englisch.

I want to replace the Player-Object with a PlayerDead-Object when the players health reaches 0.

The server is checking the health of the player and is running the code below:

 [Command]
 void CmdRespawnPlayer () 
 {
         GameObject go = Instantiate (playerDeadPrefab, Vector3.zero, Quaternion.identity) as GameObject;
         NetworkServer.Spawn (go);
         
         NetworkServer.ReplacePlayerForConnection (connectionToClient, go, 0);
 
         NetworkServer.Destroy (gameObject);
     }

When I host a LAN-Game and the player dies, the new deadPlayerPrefab spawns and changes to the new object. BUT when I connect with a second client with the same computer and player 1 dies, player 2 is changing his playerObject too. (The old Player-Object 2 is retained)

What is the Problem? maybe is there a problem with 'connectionToClient' ?

Thanks for you help ;)

Dear Dosenbiiir