Variable is not updated

Hello everyone, I'm new to unity and I've faced this problem I hope you help me with it.

I'm making a block breaker game like arkanoid game and I'm trying to load the next level when I hit the destroy all the bricks in the game, so I made a static integer variable called (blocksCount) that counts the number of the blocks in the game and each time I destroy a block I decrements the (blockCount) by 1 until it becomes 0 so I load the Win screen.

this is my code :-

         using System.Collections;
         using System.Collections.Generic;
         using UnityEngine;
 
         public class HitCounter : MonoBehaviour {
     
     private int hitTimes;
     private LevelManager levelmanager;
     public Sprite[] sprites;
     private static int bricksCount=0;
     // Use this for initialization
     void Start () {
         hitTimes = 0;
         levelmanager = GameObject.FindObjectOfType<LevelManager> ();
         if(this.tag=="Breakable")
         bricksCount++;
     }
     
     // Update is called once per frame
     void Update () {
         if (bricksCount <= 0) {
             levelmanager.loadNextLevel ();
         } else
             print ("brlocks remaining are " + bricksCount);
 
 
     }
     void OnCollisionEnter2D (Collision2D collision)
     {
         if (this.tag == "Breakable")
             executeAction ();
 }
 
     void executeAction()
     {
         int maxHits = sprites.Length+1;
         hitTimes++; //increasing the total number of block hits
         //TODO ask why we destroy a game object and how does we know that the game object is the specified block
         if (hitTimes >= maxHits) {
             bricksCount--;
             DestroyObject (gameObject);
 
         }
         else {
             if(sprites [hitTimes - 1]!=null)
             this.GetComponent<SpriteRenderer> ().sprite = sprites [hitTimes - 1];
         }
     }
     }
 

The problem is that when I destroy the last block in the game it doesn't load the next level I tried print a message shows how many bricks are still inside the update method, but unfortunatly it says there stills another 1 block but actually all blocks are destroyed.

I've fixed that by moving the code from the update method into the ((OnCollisionEnter2D)) method and that worked perffectly.

as follows:-

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class HitCounter : MonoBehaviour {
     
     private int hitTimes;
     private LevelManager levelmanager;
     public Sprite[] sprites;
     private static int bricksCount=0;
     // Use this for initialization
     void Start () {
         hitTimes = 0;
         levelmanager = GameObject.FindObjectOfType<LevelManager> ();
         if(this.tag=="Breakable")
         bricksCount++;
     }
     
     // Update is called once per frame
     void Update () {
         
     }
     void OnCollisionEnter2D (Collision2D collision)
     {
         if (this.tag == "Breakable")
             executeAction ();
 }
 
     void executeAction()
     {
         int maxHits = sprites.Length+1;
         hitTimes++; //increasing the total number of block hits
         //TODO ask why we destroy a game object and how does we know that the game object is the specified block
         if (hitTimes >= maxHits) {
             bricksCount--;
             DestroyObject (gameObject);
             if (bricksCount <= 0) {
                 levelmanager.loadNextLevel ();
             } else
                 print ("brlocks remaining are " + bricksCount);
 
 
         }
         else {
             if(sprites [hitTimes - 1]!=null)
             this.GetComponent<SpriteRenderer> ().sprite = sprites [hitTimes - 1];
         }
     }
     }
 
 
 

Could someone tell me why that happened ?? where the previous code is right and thanks in advance.