Unity Stops Running

I write this line of code in order to put a limit to spawned objects in the scene but when "powerUpsOnPlatform" hit the maximum value unity stops responding.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class PowerUpSpawner : MonoBehaviour
 {
     [SerializeField] private GameObject[] powerUps;
      private GameHandler gameHandler;
     private float xBorder = 11.5f;
     private float zBorder = 10;
     private PlayerController playerController;
     public int powerUpsOnPlatform;
     void Start()
     {
         playerController = GameObject.Find("Player").GetComponent<PlayerController>();
         gameHandler = GameObject.Find("GameHandler").GetComponent<GameHandler>();
         StartCoroutine(PowerSpawner());
     }
 
     // Update is called once per frame
     void Update()
     {
        /* if (powerUpsOnPlatform < 3)
         {
             StartCoroutine(PowerSpawner());
         }*/
     }
 
     IEnumerator PowerSpawner()
     {
         while (!gameHandler.gameOver()) 
         {
             if (powerUpsOnPlatform < 3) 
             {
                 float spawnTime = Random.Range(5, 10);
                 powerUpsOnPlatform++;
                 yield return (new WaitForSeconds(spawnTime));
                 Instantiate(powerUps[0], GenerateRandomSpawnPosition(), Quaternion.identity);
             }
             
         }
     }
 
     private Vector3 GenerateRandomSpawnPosition()
     {
         float xBorders;
         float zBorders;
         xBorders = Random.Range(-xBorder, xBorder);
         zBorders = Random.Range(-zBorder, zBorder);
         Vector3 spawnPos = new Vector3(xBorders, 0, zBorders);
         return spawnPos;
     }
     public void PowerUpDecreaser()
     {
         powerUpsOnPlatform--;
     }
 }