Bug FetchConfigsAsync does not work and gets stuck!

Hi. Please help me solve the problem!
Trying to get values from "Remote Configs" and gets stuck on WebGL.
Everything is fine in the editor, I get all the necessary values without any problems! But not WebGL!

Code (CSharp):

1. using System.Collections;
2. using Unity.Services.Authentication;
3. using Unity.Services.Core;
4. using UnityEngine;
5. using ConfigManager = Unity.Services.RemoteConfig.ConfigManager;
6.  
7. public class CanvasTest : MonoBehaviour
8. {
9.   private struct userAttributes { }
10.   private struct appAttributes { }
11.  
12.   // ============================================================================
13.   private void Start()
14.   {
15.     StartCoroutine(nameof(StartAsync));
16.   }
17.  
18.   // ============================================================================
19.   private IEnumerator StartAsync()
20.   {
21.     #region UnityRemoteConfig
22.  
23.     DebugX.Log("Unity Remote config initialize...");
24.     ConfigManager.SetEnvironmentID(Global.UnityRemoteConfigEnvID);
25.     ConfigManager.SetPlayerID("...");
26.  
27.     var initTask = UnityServices.InitializeAsync();
28.     yield return new WaitUntil(() => initTask.IsCompleted);
29.  
30.     if (!AuthenticationService.Instance.IsSignedIn)
31.     {
32.       var authTask = AuthenticationService.Instance.SignInAnonymouslyAsync();
33.       yield return new WaitUntil(() => authTask.IsCompleted);
34.     }
35.  
36.     DebugX.Log("Wait for fetching remote config (10)");
37.     yield return new WaitForSeconds(10);
38.  
39.     DebugX.Log("Fetching remote config from Unity...");
40.  
41.     // STUCK on this
42.     var fetchTask = ConfigManager.FetchConfigsAsync<userAttributes, appAttributes>(new userAttributes(), new appAttributes());
43.     yield return new WaitUntil(() => fetchTask.IsCompleted);
44.  
45.     // !!!!!!!! This log and next code is no longer executed !!!!!!!
46.     DebugX.Log("Remote config from Unity acepted.");
47.  
48.     // Log Remote Config
49.     var message = ConfigManager.appConfig.GetString("Message");
50.     var messageTime = ConfigManager.appConfig.GetLong("MessageTime");
51.     var minVersion = ConfigManager.appConfig.GetInt("MinVersion");
52.     var showBlockMessage = ConfigManager.appConfig.GetBool("ShowBlockMessage");
53.     DebugX.Log($"Remote config: message({message}), messageTime({messageTime}), minVersion({minVersion}), showBlockMessage({showBlockMessage})");
54.    
55.     #endregion UnityRemoteConfig
56.   }
57. }
58.  

Get this result in browser, the response is obtained, but the function gets stuck: