Problem with the gun reloading

Hello !

I'm trying to make a reload on "r' pressing. Every time you press r, there's one more bullet in your magazine and one less in your stock. They are visualized by lights (every time you press "r", a lightbulb goes on on the rifle, and one goes off on the stock).

The problem is that it reloads at full magazine capacity everytime, and not just one bullet. I really don't know what's wrong. Can someone please help ? Thanks.

  IEnumerator Reloading()
     {
        
  
         OnReloading.Invoke();
         //_animator.SetBool("reloading", true);
         yield return new WaitForSeconds(_reloadTime);
         _canShoot = false;
         LightOnReload();
         BackpackLightManager();
         MagazineManager();    
         SetMagazineLight();
         _emptyFlickeringLight.SetActive(false);
         _canShoot = true;

         GameState._isReloading = false;
          
     }

void BackpackLightManager() {

     if (backpack < 19)
     {
        _playerBackpackLight[backpack].SetActive(false);
        backpack+=1;
      
     }

     else if (backpack == 19)
     {
        _playerBackpackLight[backpack].SetActive(false);
     }

     else { Debug.Log("Plus de munitions dans le sac"); }
 }
     void MagazineManager()
     {
         if (_magazineCapacity < 4)
         {
             _magazineCapacity+=1;
 
         }
 
       
     }
     void LightOnReload()
     {
 
         if (bulb == 0)
         {
             Debug.Log("munitions au complet");
         }
 
         else if (bulb > 0)
         {
             _playerBulbLight[bulb].SetActive(false)
             bulb-=1;
             _playerBulbLight[bulb].SetActive(true)
 
         }
 

     }