Function from other script not getting called.

I'm trying to call a function from my PlayerController class from another class, but for some reason the function is never getting called. Any ideas why?

 private void FreezePlayers(GameObject player)
     {
         string playerID = player.GetComponent<PlayerModel>().playerID;
         
         foreach(GameObject p in GameManager.instance.players)
         {
             if(p.GetComponent<PlayerModel>().playerID != playerID)
             {
                 Debug.Log("Freeze Function Reached");
                 p.GetComponent<PlayerController>().Freeze();
             }
         }
     }

In the PlayerController class:

 public IEnumerable Freeze()
     {
         Debug.Log("Freeze Function Called");
         isFrozen = true;
         Transform iceBlock = Instantiate(GameManager.instance.iceBlockPrefab, transform.position, Quaternion.identity);
         iceBlock.parent = transform;
         
 
         yield return new WaitForSeconds(2.0F);
 
         isFrozen = false;
         Destroy(iceBlock);
     }

I know the freeze function is getting reached because of the print statements I added. "Freeze Function Reached" gets printed but "Freeze Function Called" never gets printed.