Coroutine not working as expected

I'm trying to run a couple of coroutines that will ultimately do this: generate a random int and then start the attack function that corresponds to that int, then wait some amount of time before repeating the process.But for some reason the way my code is now random ints are being generated constantly so the enemy is just shooting every attack out extremely quickly. Can anyone help me find the flaw in my code?

  private int[] elements;
     private int myElement;
     public float timeBetweenAttacks;
     public bool runningCR;
 
     public Transform wavePoint, slicePoint, shootPoint;
 
     public bool runningAtk;
     public GameObject bossAtkWave, bossAtkSlice, bossAtkShoot;
 
 
     // Start is called before the first frame update
     void Start()
     {
         elements = new int[3];
         //BossBattleTrigger.instance = GetComponent<BossBattleTrigger>();
     }
 
     // Update is called once per frame
     void Update()
     {
         if (!runningCR && !runningAtk)
         {
             StartCoroutine(ChooseAttack());
         }
     }
 
 
 
     public IEnumerator ChooseAttack()
     {
         if (!runningAtk)
         {
             runningCR = true;
             yield return new WaitForSeconds(timeBetweenAttacks * Time.deltaTime);
 
             RandomNumberGenerator();
 
             Debug.Log(myElement);
             //Debug.Log(elements.Length);
 
             switch (myElement)
             {
                 case 0:
                     StartCoroutine(Wave());
                     break;
 
                 case 1:
                     StartCoroutine(Slice());
                     break;
 
                 case 2:
                     StartCoroutine(Shoot());
                     break;
             }
 
             //yield return new WaitForSeconds(timeBetweenAttacks * Time.deltaTime);
             runningAtk = true;
             runningCR = false;
         } else if (runningAtk)
         {
             yield break;
         }
     }
 
     public IEnumerator Wave()
     {
         //runningAtk = true;
         //do atk stuff
         Instantiate(bossAtkWave, wavePoint.transform.position, wavePoint.transform.rotation);
         yield return new WaitForSeconds(timeBetweenAttacks * Time.deltaTime);
         runningAtk = false;
         //Debug.Log("Wave");
     }
 
     public IEnumerator Slice()
     {
         //runningAtk = true;
         Instantiate(bossAtkSlice, slicePoint.transform.position, slicePoint.transform.rotation);
         yield return new WaitForSeconds(timeBetweenAttacks * Time.deltaTime);
         runningAtk = false;
         //Debug.Log("SliceRunning");
     }
 
     public IEnumerator Shoot()
     {
         //runningAtk = true;
         Instantiate(bossAtkShoot, shootPoint.transform.position, shootPoint.transform.rotation);
         yield return new WaitForSeconds(timeBetweenAttacks * Time.deltaTime);
         runningAtk = false;
         //Debug.Log("ShootRunning");
     }
 
     private void RandomNumberGenerator()
     {
         myElement = Random.Range(0, elements.Length);
     }