Selection Circle Not Disappearing

I'm trying to make an RTS game, like Age of Mythology. When I run my code, however, it doesn't give me any error messages, but the Select Circle doesn't disappear. Here's my code:

 public class RTSObject : MonoBehaviour
 {
     public int maxHitPoints = 1000, raakiteCost = 100, powerCost = 100, damage = 10, lineOfSight = 10;
     public string objectName;
     public ResourceManager.DamageType damageType = ResourceManager.DamageType.hack;
     public float hackArmor, pierceArmor, necroticArmor, crushArmor;
     public bool Resurrectable = false;
     public RTSPlayer player;
     public Mesh objectMesh;
     //public int ownIndex;
     public bool selected = false;
     public bool mobile = false;
     public Renderer selectCircleRenderer;
     public GameObject selectCircleRef;
 
     private int hitPoints;
 
     // Start is called before the first frame update
     public virtual void Start()
     {
         //replace this with the building stuff
         hitPoints = maxHitPoints;
         //but not this
         selectCircleRef = gameObject.transform.GetChild(gameObject.transform.childCount - 1).gameObject;
         selectCircleRenderer = selectCircleRef.GetComponent<Renderer>();
         selectCircleRef.SetActive(false);
     }
 
     // Update is called once per frame  
     public virtual void Update()
     {
         selected = player.selects.Contains(this);
         //should this object be dead?
         if (hitPoints <= 0 || (selected && Input.GetKey("delete"))) Die();
         selectCircleRef = gameObject.transform.GetChild(gameObject.transform.childCount - 1).gameObject;
         selectCircleRenderer = selectCircleRef.GetComponent<Renderer>();
         if (selected && !selectCircleRenderer.enabled)
         {
             selectCircleRenderer.enabled = false; ;
         }
         else if (!selected && selectCircleRenderer.enabled)
         {
             selectCircleRenderer.enabled = true;
         }
     }
 
     public void MoveTo(Vector3 destination)
     {
         //AI Movement
     }
 
     protected virtual void Die()
     {
         player.selects.Remove(this);
         selected = false;
         if (Resurrectable == false)
         {
             Destroy(gameObject);
         }
         else
         {
             //"die" here
         }
     }
 }
 

and a screenshot of my RTSObject prefab (though it isnt a prefab yet):