[Unity 5]matchmaking : matches not visible

I need your help please because I have an issue about matchmaking. I try to make a Pong playable online. When i use NetworkHUD, and I use Matchmaker, I can create a match, and the other app (on the same computer for now) detach it and can join it. But, when I don't use it, but I use matchmaker manually, I can create a match, I have a success response, I can find this match in the same app, but, in my second app, I can't find match created by the first app.

Can you help me?

Here are two functions in which I create match :

 public void matchmaking()
     {
         nm.StartMatchMaker();
         networkMatch.ListMatches(0, 20, "", OnMatchList);
         Debug.LogError ("NBR MATCH " +matchList.Count);
         if (matchList.Count == 0)
         {
             CreateMatchRequest match = new CreateMatchRequest();
             match.name = "OrionPongRoom";
             match.size = 2;
             match.advertise = true;
             match.password = "";
             networkMatch.CreateMatch(match, OnMatchCreate);
         }
         else
             Debug.Log ("******matches found"+matchList.Count);
     }
    void OnMatchCreate(CreateMatchResponse matchResponse)
 {
     if (matchResponse.success)
     {
         Debug.LogError("Create match succeeded");
         matchCreated = true;
         MatchInfo matchInfo = new MatchInfo(matchResponse);
         Utility.SetAccessTokenForNetwork(matchResponse.networkId, new NetworkAccessToken(matchResponse.accessTokenString));
         nm.StartHost(matchInfo);
         NetworkServer.Listen(9000);
         //NetworkServer.Listen(new MatchInfo(matchResponse), 9000);
     }
     else
     {
         Debug.LogError ("Create match failed");
     }
 }

You need to write

     if (matchList.Count == 0)
     {
         CreateMatchRequest match = new CreateMatchRequest();
         match.name = "OrionPongRoom";
         match.size = 2;
         match.advertise = true;
         match.password = "";
         networkMatch.CreateMatch(match, OnMatchCreate);
     }
     else
         Debug.Log ("******matches found"+matchList.Count);

in OnMatchList method.

void OnMatchList(ListMatchResponse matchList)
{
  if (matchList.Count == 0)
         {
             CreateMatchRequest match = new CreateMatchRequest();
             match.name = "OrionPongRoom";
             match.size = 2;
             match.advertise = true;
             match.password = "";
             networkMatch.CreateMatch(match, OnMatchCreate);
         }
         else
             Debug.Log ("******matches found"+matchList.Count);
}

Because of Network Delays etc, matchmaking server can not send response synchronous.