Fixing a timing issue with the lobby heartbeat, where you could leave a lobby right before the heartbeat elapses and then create a new one, and the heartbeat would still trigger with the old one.

Assets/Scripts/Lobby/LobbyAsyncRequests.cs

         {
             m_currentLobbyId = null;
             m_lastKnownLobby = null;
+            m_heartbeatTime = 0;
         }
 
         private void UpdateLobby(float unused)