NetworkBehaviour-MutiTank(Clone) is being destroyed while NetworkObject-MutiTank(Clone) is still spawned! (could break state synchronization) UnityEngine.Debug:LogWarning (object)

I am getting this error when trying to add the Multiplayer feature to my game. The server and Client can connect to each other but cannot synchronize
I have read it here: https://forum.unity.com/threads/networktransform-not-working-on-client.334844/
But it doesn’t help.

You need to call Despawn() on the MutiTank instance.