Trying to make "Gallery Unlocker" script with Singleton

Hello, my game has many scenes and I put these scenes into main menu. However, if player didn't play that scene, player shouldn't enter the scene in main menu gallery section.

This is my Singleton script: using System.Collections; using System.Collections.Generic; using UnityEngine;

 public abstract class Singleton<T> : MonoBehaviour where T : Component
 {
     
     #region Fields
 
     /// <summary>
     /// The instance.
     /// </summary>
     private static T instance;
 
     #endregion
 
     #region Properties
 
     /// <summary>
     /// Gets the instance.
     /// </summary>
     /// <value>The instance.</value>
     public static T Instance
     {
         get
         {
             if ( instance == null )
             {
                 instance = FindObjectOfType<T> ();
                 if ( instance == null )
                 {
                     GameObject obj = new GameObject ();
                     obj.name = typeof ( T ).Name;
                     instance = obj.AddComponent<T> ();
                 }
             }
             return instance;
         }
     }
 
     #endregion
 
     #region Methods
 
     /// <summary>
     /// Use this for initialization.
     /// </summary>
     protected virtual void Awake ()
     {
         if ( instance == null )
         {
             instance = this as T;
             DontDestroyOnLoad ( gameObject );
         }
         else
         {
             Destroy ( gameObject );
         }
     }
 
     #endregion
     
 }

galleryMenuChecker.cs (Singleton in main menu) using System.Collections; using System.Collections.Generic; using UnityEngine;

 public class galleryMenuChecker : Singleton<galleryMenuChecker>
 {
     public bool fromGallery1 = false;
     public bool fromGallery2 = false;
     public bool fromGallery3 = false;
     public bool fromGallery4 = false;
 
     public void DirectScene1()
     {
         if (GameManager.Instance.Scene1AnimationUnlocked == false)
         {
             Debug.Log("You haven't played this scene yet!");
         }
         else if (GameManager.Instance.Scene1AnimationUnlocked == true)
         {
             GameObject.Find("LevelLoader").GetComponent<LevelLoader>().Scene1();
             fromGallery1 = true;
         }
     }
 
     public void DirectScene2()
     {
         if (GameManager.Instance.Scene2AnimationUnlocked == false)
         {
             Debug.Log("You haven't played this scene yet!");
         }
         else if (GameManager.Instance.Scene2AnimationUnlocked == true)
         {
             GameObject.Find("LevelLoader").GetComponent<LevelLoader>().Scene2();
             fromGallery2 = true;
         }
 
     }
 
 
 }
 

And my Game Manager (Singleton). This one has booleans only.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class GameManager : Singleton<GameManager>
 {
     // Scene 4 Key is Taken or Not?
     public bool S4_Keycard = false;
 
     // Unity Scene Animations Unlocked or Not?
     public bool Scene1AnimationUnlocked = false;
     public bool Scene2AnimationUnlocked = false;
     public bool Scene3AnimationUnlocked = false;
     public bool Scene4AnimationUnlocked = false;
 }
 

When the player play scene1, I execuete this command in Start(): GameManager.Instance.Scene1AnimationUnlocked = true;

So far so good, everything works fine. Buttons works fine for once. But when I complete the playing of scene1 and return to main menu with ESC pause menu, button no more works.

I checked the situation in edit mode and Singletons works fine, booleans are updated, yet button click does not work.

What did I wrong? Or is there any better way to make a gallery unlocker in Unity? Thank you.

More images: https://imgur.com/a/xa0jHrE