Question AR Foundation - Multiple Tracked Image AR project not working

I have a AR project in which there are multiple image targets which is being tracked and their corresponding prefabs that gets instantiated once the image is tracked. As per the script, the activation/deactivation of the prefab depends upon the tracked image's tracking state. Now what I want is, to keep a particular prefab activated even if that tracked image's tracking is lost, and that prefab should be deactivated only when any other target images are tracked. This is the script, what changes should I make to achieve this??

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.XR.ARFoundation;
5. using UnityEngine.XR.ARSubsystems;
6. using UnityEngine.Events;
7. using TMPro;
8.  
9. [RequireComponent(typeof(ARTrackedImageManager))]
10. public class PlaceTrackedImages : MonoBehaviour
11. {
12.     private ARTrackedImageManager _trackedImagesManager;
13.     public GameObject[] ArPrefabs;
14.     private readonly Dictionary<string, GameObject> _instantiatedPrefabs = new Dictionary<string, GameObject>();
15.     public UnityEvent order;
16.     public TextMeshProUGUI status;
17.  
18.     private void Awake()
19.     {
20.         _trackedImagesManager = GetComponent<ARTrackedImageManager>();
21.     }
22.  
23.     private void OnEnable()
24.     {
25.         _trackedImagesManager.trackedImagesChanged += OnTrackedImagesChanged;
26.     }
27.  
28.     private void OnDisable()
29.     {
30.         _trackedImagesManager.trackedImagesChanged -= OnTrackedImagesChanged;
31.     }
32.  
33.     private void OnTrackedImagesChanged(ARTrackedImagesChangedEventArgs eventArgs)
34.     {
35.         // New tracked images
36.         foreach (var trackedImage in eventArgs.added)
37.         {
38.             var imageName = trackedImage.referenceImage.name;
39.             foreach (var curPrefab in ArPrefabs)
40.             {
41.                 if (string.Compare(curPrefab.name, imageName, System.StringComparison.OrdinalIgnoreCase) == 0
42.                     && !_instantiatedPrefabs.ContainsKey(imageName))
43.                 {
44.                     var newPrefab = Instantiate(curPrefab, trackedImage.transform);
45.                     order.Invoke();
46.                     _instantiatedPrefabs[imageName] = newPrefab;
47.                 }
48.             }
49.         }
50.  
51.         // Updated tracked images
52.         foreach (var trackedImage in eventArgs.updated)
53.         {
54.             if (_instantiatedPrefabs.TryGetValue(trackedImage.referenceImage.name, out var prefab))
55.             {
56.                 status.text = trackedImage.referenceImage.name;
57.                 prefab.SetActive(trackedImage.trackingState == TrackingState.Tracking);
58.             }
59.         }
60.  
61.         // Removed tracked images
62.         foreach (var trackedImage in eventArgs.removed)
63.         {
64.             if (_instantiatedPrefabs.TryGetValue(trackedImage.referenceImage.name, out var prefab))
65.             {
66.                 Destroy(prefab);
67.                 _instantiatedPrefabs.Remove(trackedImage.referenceImage.name);
68.             }
69.         }
70.     }
71. }