Trouble with Object Pooled Enemy Waves

Hopefully someone can help me with this issue. I'm trying to couple an IEnumerator with my object pooling script to instantiate enemies in waves. But I can't get them to instantiate without immediately destroying themselves 2 or 3 times and then instantiating one wave of enemies and never spawning again. Can anyone help me see where I'm going wrong here?

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class SpawnMaster : MonoBehaviour {
 
  public int enemyCount = 4;
  public float spawnWait=0.5f;
  public float startWait=1;
  public float waveWait=3;            
  public Transform[] spawnPoints; 
  private int currentWave = 0;
  private int waveCount = 10;
  
  private IEnumerator spawnWaves;
  private IEnumerator goHorde;
     bool isSpawning = false;
  
 
  
  void Update()
  {
     if(!isSpawning)
     {
         isSpawning = true;
        StartCoroutine(SpawnWaves(currentWave));
     }
  }
 
  IEnumerator SpawnWaves (int currentWave)
  {
      Debug.Log("Spawning " + currentWave + "currentWave");
               for (int i = 0; i < waveCount; i++)
               {
                  StartCoroutine(GoHorde());
               }
               currentWave += 1;
          yield return new WaitForSeconds (waveWait);
           
         //We've spawned, so start another spawn    
         isSpawning = false;
  }
  
  IEnumerator GoHorde()
  {
      GameObject beetle01 = BeetlePool.current.GetPooledObject();
  if(beetle01 == null)
  yield return null;
  
  // Only pick a new spawn point once per wave
  int spawnPointIndex = Random.Range (0, spawnPoints.Length);
  
     for (int j = 0; j < enemyCount; j++)
     {
     beetle01.transform.position = spawnPoints[spawnPointIndex].position;
     beetle01.transform.rotation = spawnPoints[spawnPointIndex].rotation;
     beetle01.SetActive(true);   
     yield return new WaitForSeconds (spawnWait);
     }      
  }
 }

Thanks in advance, Milan