Google Play Realtime Quick Match Fails

I'm developing a game using Google Play for realtime multiplayer. The plugin I used is the Google official one: https://github.com/playgameservices/play-games-plugin-for-unity.

Basically I followed every step based on the documentation. I'm able to sign in, post score and see the leaderboard. However, I failed every time creating a quick game. The console shows that after calling quickGame(), OnRoomSetupProgress(float percent) method was actually never called. It directly goes to OnRoomConnected(bool success) which fails every time.

I tried to create a quick game from invitation. I was able to see my friend list in Google Play UI, but I didn't receive any invitation and the game creation failed too. I really don't know what I did wrong.

Thanks in advance for any help I could get. My codes here:

 using UnityEngine;
 using System.Collections;
 using UnityEngine.UI;
 using UnityEngine.SocialPlatforms;
 using GooglePlayGames;
 using GooglePlayGames.BasicApi;
 using GooglePlayGames.BasicApi.Multiplayer;
 using System.Collections.Generic;
 
 
 public class GP : MonoBehaviour, RealTimeMultiplayerListener{
     
         const string learderboard="xxx";
         const int MinOpponents = 1, MaxOpponents = 1;
         const int GameVariant = 0;
 
         // Variables for implementing interface
         public bool m_roomLoaded = false;
         public bool m_peerConnected = false;
         public float m_roomProgress = 0.0f;
         public bool m_messageReceived = false;
         public string m_message = "";
         Invitation mIncomingInvitation = null;
 
         // Use this for initialization
         void Start () {
             PlayGamesClientConfiguration config = new PlayGamesClientConfiguration.Builder()
                 // registers a callback to handle game invitations.
                 .WithInvitationDelegate(OnInvitationReceived) 
                     .Build();
             
             PlayGamesPlatform.InitializeInstance(config);
             
             // recommended for debugging:
             PlayGamesPlatform.DebugLogEnabled = true;
             PlayGamesPlatform.Activate ();
             Login ();
         }
 
         public void Login()
         {
             Social.localUser.Authenticate((bool success) => {
                 if(success)
                 {
                     print ("Success logged in");
                 }
                 else
                 {
                     print ("log in failed");
                 }
             });
         }
 
         public void PostScore()
         {
             Social.ReportScore(12345, learderboard, (bool success) => {
                 if(success)
                 {
                     print("posted score");
                 }
                 else
                 {
                     print("post failed");
                 }
             });
         }
 
         public void ShowLeaderboard()
         {
             PlayGamesPlatform.Instance.ShowLeaderboardUI(learderboard);
         }
 
         public void SignOut()
         {
             PlayGamesPlatform.Instance.SignOut();
         }
 
         public void quickGame()
         {
             PlayGamesPlatform.Instance.RealTime.CreateQuickGame(1, 1, 0, this);
         }
 
         public void inviteFriendGame()
         {
             PlayGamesPlatform.Instance.RealTime.CreateWithInvitationScreen(MinOpponents, MaxOpponents,GameVariant,this);
         }
 
         public void accept_inbox()
         {
             PlayGamesPlatform.Instance.RealTime.AcceptFromInbox(this);    
         }
 
 //        public void acceptInvitation()
 //        {
 //            //Invitation invitation = ....;  // (obtained via delegate)
 //            PlayGamesPlatform.Instance.RealTime.AcceptInvitation(invitationId, invitation.InvitationId);
 //        }
 
         // implement the realtime listener interface
         public void OnRoomSetupProgress(float percent) {
             m_roomProgress = percent;
             print(m_roomProgress);
         }
         
         public void OnRoomConnected(bool success) {
             m_roomLoaded = success;
             if (success) {
                 print(“Success”);
             } else {
                 print(“Error”);
             }
         }
 
         public void getParticipantID()
         {
             Participant myself = PlayGamesPlatform.Instance.RealTime.GetSelf();
         }
 
         public List<Participant> getPlayerList()
         {
             List<Participant> participants = PlayGamesPlatform.Instance.RealTime.GetConnectedParticipants();
             return participants;
         }
 
         public void OnLeftRoom() {
             m_roomLoaded = false;
         }
         
         public void OnPeersConnected(string[] participantIds) {
             m_peerConnected = true;
         }
         
         public void OnPeersDisconnected(string[] participantIds) {
             m_peerConnected = false;
         }
 
         public void OnRealTimeMessageReceived (bool isReliable, string senderId, byte[] data)
         {
             throw new System.NotImplementedException ();
         }
 
         public void LeaveGame()
         {
             PlayGamesPlatform.Instance.RealTime.LeaveRoom();
         }
 
         public void OnInvitationReceived(Invitation invitation, bool shouldAutoAccept) {
             if (shouldAutoAccept) {
                 // Invitation should be accepted immediately. Instance happens if the user already
                 // indicated (through the notification UI) that they wish to accept the invitation,
                 // so we should not prompt again.
                 ShowWaitScreen();
                 PlayGamesPlatform.Instance.RealTime.AcceptInvitation(invitation.InvitationId, this);
             } else {
                 // The user has not yet indicated that they want to accept Instance invitation.
                 // We should *not* automatically accept it. Rather we store it and 
                 // display an in-game popup:
                 mIncomingInvitation = invitation;
             }
         }
 
         void ShowWaitScreen()
         {
             //To Do..
         }
     
 }