References missing after stop hosting through NetworkLobbyManager. Bug?

It’s about some strange reference missing problem

  1. I created a simple project. Added a LobbyMgr object with NetworkLobbyManager and NetworkManagerHUD components. And my “LobbyMgr” script to it.

  2. That LobbyMgr are quite simple. It only defines 4 public references and it’s with no logic code.
    public class LobbyMgr : MonoBehaviour {
    public Button button1;
    public Button button2;
    public Text buttonText1;
    public Text buttonText2;
    // Use this for initialization
    void Start () {

    }

    // Update is called once per frame
    void Update () {

    }
    }

3.Then click the “LAN Host” button, provided by the HUD component, to start hosting a game.
4.Stop hosting game by click the “Stop” button provided by the HUD component. No error was reported.

But!!!
The references are gone!!

I tried out that only the GameObject with NetworkLobbyManager will lose references. Other objects’s references will still be there.

Is it a but or some rules ?

By the way. I’m using 5.3.3f1 personal version