Host's PlayerObject becomes null after Despawning a transferred client PlayerObject (DontDestroyWithOwner)

[T-Huckle]

Description

The PlayerObject of the host appears to be nulled out when a different object (of the same type) gets despawned and has is also owned by the host.

Reproduce Steps

Have a network object that gets marked with
GetComponent<NetworkObject>().DontDestroyWithOwner = true;

In my setup, my player object was not set as the default player object. Instead I explicitly spawned with SpawnAsPlayerObject

When the client disconnects - set a delayedDespawn coroutine, then despawn that object. After which, the hosts PlayerObject becomes null

private IEnumerator DelayDespawnCoroutine(PlayerController pc, PlayerController hostPc) {
    // Host is always ID 0
    Debug.Log("Host player number: " + NetworkManager.Singleton.ConnectedClients[0].PlayerObject?.GetComponent<PlayerController>().PlayerNumber);

    yield return new WaitForSeconds(5);

    var obj = pc.GetComponent<NetworkObject>();
    if (obj != null && obj.IsSpawned) {
        // Orphaned Network Object now as the same OwnerClientId as the host
        Debug.Log($"Despawning object with OwnerClientId: {obj.OwnerClientId}");

        // We see this print out the hosts PlayerNumber (1 in this scenario)
        Debug.Log("Host player number: " + NetworkManager.Singleton.ConnectedClients[0].PlayerObject?.GetComponent<PlayerController>().PlayerNumber);

        // We see this print out the playerNumber of the disconnected client (3 in this scenario - these are different object)
Debug.Log("Despawning Player Number: " + pc.PlayerNumber);
        
        //Despawn and destroy the NetworkObject 
        obj.Despawn(true);

        // No Longer prints out 1 as PlayerObject has now become null.
        Debug.Log("Host player number: " + NetworkManager.Singleton.ConnectedClients[0].PlayerObject?.GetComponent<PlayerController>().PlayerNumber);

    }
    else {
        Debug.Log("No despawn: ");
        Debug.Log(obj);
    }
}

Actual Outcome

Host loses a reference to its PlayerObject

Expected Outcome

The NetworkObject succesfully despawns and the Host's PlayerObject remains the same

Environment

• OS: Windows 11
• Unity Version: 6000.3.8f1
• Netcode Version: 2.11.0
• Netcode Topology: Client-Server

Additional Context

Can work around by reassigning the PlayerObject

        obj.Despawn(true);
        if (NetworkManager.Singleton.ConnectedClients.TryGetValue(0, out var hostClient) &&
            hostClient.PlayerObject == null) {
            hostClient.PlayerObject = hostPc.GetComponent<NetworkObject>();
            Debug.Log("Restored host PlayerObject after despawn");
        }

I believe the issue is here in NetworkSpawnManager inside OnDespawnObject.

if (networkObject.IsPlayerObject)
           {
               RemovePlayerObject(networkObject, destroyGameObject);
           }

or inside RemovePlayerObject

   if (m_PlayerObjectsTable.ContainsKey(playerObject.OwnerClientId))
            {
                m_PlayerObjectsTable[playerObject.OwnerClientId].Remove(playerObject);
                if (m_PlayerObjectsTable[playerObject.OwnerClientId].Count == 0)
                {
                    m_PlayerObjectsTable.Remove(playerObject.OwnerClientId);
                }
            }

Should check to make sure that m_PlayerObjectsTable[playerObject.OwnerClientId] == playerObject

[EmandM]

To clarify the order of operations, does this roughly summarize what you're seeing?

1. Connect a new client: clientA
2. Server manually spawns a player for clientA and gives clientA ownership.
3. When clientA disconnects, start a coroutine that will wait for an amount of time
4. After waiting, the host despawns the player's NetworkObject
5. The code ends up despawning the host's player object rather than clientA's lingering object

The ownership of clientA's player object will be moved to the host when clientA disconnects. This means when RemovePlayerObject is called, the host will be the owner of that object, which causes the issue you're seeing in RemovePlayerObject.

Out of interest, what's the use case for the delayed player despawn? How do you expect the player network object to behave once the associated player is disconnected?

[T-Huckle]

Yes that is correct except one detail - the correct object is in fact being deleted. But m_PlayerObjectsTable.Remove(playerObject.OwnerClientId); also removes the PlayerObject for the host.

edit: to clarify- the hosts playerObject is never actually deleted/removed from the scene - but just Nulled out it seems on the PlayerObject

The use case is I want players characters to stay in the game for 10 or so seconds to stop them alt f4'ing in order to avoid being killed by another player. Similar to how DayZ handles log offs