Best practices for Joining and Leaving multiple Sessions

This guide outlines recommended steps when using the Multiplayer Services SDK to ensure your game cleanly disconnects from previous matches before starting a new one in multi-match game sessions

When using Multiplayer Sessions:

• Always use ISession.LeaveAsync() to leave a session. 
  This is the only correct method. It internally shuts down NGO (Netcode for GameObjects), awaits OnClientStopped, and then calls Dispose(), which restores NetworkManager.NetworkConfig.
   
• Do not call NetworkManager.Shutdown() manually. 
  Calling LeaveAsync() automatically fires the SDK's internal OnManagerStopped sequence, which includes a full teardown of the NetworkManager. A manual shutdown will conflict with this execution and cause unexpected behaviour.
   
• Manage NetworkManager.SceneManager subscriptions carefully. 
  The SceneManager creates a new instance each time NGO starts. Any subscriptions made on the lobby DA session (such as OnLoadEventCompleted) become dead references after LeaveAsync(). You must unsubscribe from all scene events before calling LeaveAsync(), and then resubscribe to the new SceneManager once the new session is ready.
   
• Verify session closure via Network Manager events. 
  Even if LeaveAsync() executes fully, you should subscribe to the Network Manager events OnClientStopped and OnServerStopped to guarantee that the previous match is entirely closed before attempting to join another session.
   
• Utilize a delayed start approach. 
  You can decouple session creation from netcode initialization by omitting .WithDirectNetwork() / .WithRelayNetwork() / .WithDistributedAuthorityNetwork() when creating a session. This allows you to group players before starting the network. 
   
• Initialize the network only when ready. 
  When your lobby is ready to start connecting, start the network using StartDirectNetworkAsync(DirectNetworkOptions). This is especially helpful for transitioning players between matches without dropping them from matchmaking groups. This approach works with both RelayNetwork and DistributedAuthorityNetwork.