Bringing this thread back up because I have a similar issue with a little different end result. Same situation, game instances will need to stop and start servers from within the game. Then they will need to disconnect, stop the server and either start another one or join another one.
I had the same issue, when I used TNManager.Disconnect() and TNServerInstance.Stop(), then when I tried to use TNServerInstance.Start() It returned "Connect - false, expected a response ID, but go ERROR"
So I switched to just TNServerInstance.Stop() and that error stopped, however, now when I start the server for the second time TNManager.isHosting is false! Any thoughts?