Can't call GameCenter in my Unity game for iOS

Hello! I'm trying to integrate Game Center into my Unity 5 project and facings troubles. It seems that authentification is OK when the game starts on iOS device, a notification appears, but leaderboard button does not work, nothing happens when I tap GC button. I assigned the initiation of "ShowLeaderboard()" to GC button. Please, take a look at the script I use below. Hope to find a resolution for my issue. Thank you in advance.

 using UnityEngine;
 using UnityEngine.SocialPlatforms;
 using UnityEngine.SocialPlatforms.GameCenter;
 using System.Collections;

 public class GameCenter : MonoBehaviour {

     public string leaderboardID = "mygameleaderboard";

     void Start () {
         AuthenticateToGameCenter();
     }
 
     private bool isAuthenticatedToGameCenter;
     public static void  AuthenticateToGameCenter() {
         #if UNITY_IPHONE
         Social.localUser.Authenticate(success => {
         if (success) {
             Debug.Log("Authentication successful");
         } else {
             Debug.Log("Authentication failed");
             }
         });
         #endif
     }

     public static void ReportScore(long score, string leaderboardID) {
         #if UNITY_IPHONE
         Debug.Log("Reporting score " + score + " on leaderboard " + leaderboardID);
         Social.ReportScore(score, leaderboardID, success => {
             if (success) {
             Debug.Log("Reported score successfully");
             } else {
                 Debug.Log("Failed to report score");
                 }
             });
         #endif
     }

     //call to show leaderboard
     public static void ShowLeaderboard() {
         #if UNITY_IPHONE
         Social.ShowLeaderboardUI();
         #endif
     }
 }