finding clones and destroying them doesn't work

I am instantiating objects when a variable changes, but before I instantiate the object I find all clones and destroy them. My code looks like this:

void Update() {

     GameObject[] Clones = GameObject.FindGameObjectsWithTag("clone");

     if (Unlocked == true)
     {

         Unlocked = false;

         Debug.Log(Clones.Length);

         foreach (GameObject Clone in Clones)
         {
             Destroy(Clone);
         }

         UnlockPanel.tag = "clone";

         foreach (Unlocks Unlock in UnlocksList)
         {

             if (Unlock.TargetGenerator == "Infrastructure")
             {
                 GameObject Clone = Instantiate(UnlockPanel, InfrastructureContent);
                 var LevelText = Clone.transform.Find("UnlockLevelText");
                 LevelText.GetComponent<Text>().text = Unlock.TargetLevel.ToString();
                 var MultiplierText = Clone.transform.Find("MultiplierText");
                 if (Unlock.IsProfit == true)
                 {
                     MultiplierText.GetComponent<Text>().text = "Profits " + Unlock.MultiplierNumber + "x";
                 }
                 else
                 {
                     MultiplierText.GetComponent<Text>().text = "Profit speed " + Unlock.MultiplierNumber + "x";
                 }
                 if (Unlock.IsUnlocked == true)
                 {
                     Debug.Log("Yes");
                     Transform UnlockedOverlay = Clone.transform.Find("Unlocked");
                     UnlockedOverlay.gameObject.SetActive(true);
                 }
             }}}

The parent to where the object is being instantiated is a child of a child. Everything works apart from the part where the existing clones are being destroyed. As you can see I have put a debug.log for the array length, but that only returns zero all the time. have already a script that works the same and it works perfectly there, that script looks like this:

void Update() {

     GameObject[] Clones = GameObject.FindGameObjectsWithTag("upgradeclone");

     if (_UpgradesList.Count != UpgradesList.Count)
     {
         _UpgradesList.Clear();

         foreach (Upgrades _upgrades in UpgradesList)
         {
             _UpgradesList.Add(_upgrades);
         }

         foreach (GameObject Clone in Clones)
         {
             Destroy(Clone);
         }

         UpgradeButton.tag = "upgradeclone";
         for (int n = 0; n < 5; n++)
         {
             GameObject Clone = Instantiate(UpgradeButton, ParentObject);
             Clone.GetComponent<UpgradeScript>().InternalListItem = n;
         }

     }
 }

Can someone please help me find the error.