Having trouble with raycast detecting enemy

I have a script casting a raycast from the center of the screen at to a certain distance looking for the colliders of any enemy tagged as "enemy". But according to my debug log, it only seems to detect one specific enemy and ignores the others. From what I can see, there's nothing different about this enemy than the others (they're all from the same prefab). Here's the script:

     public bool inPlayerSight;
     public float playerSightDistance;
 
     private Animator anim;
     private DoneHashIDs hash;
     private Transform cam;
     private bool spotted;
     private GameObject enemy;
 
 
     void Awake(){
 
         anim = GetComponent<Animator>();
         hash = GameObject.FindGameObjectWithTag(Tags.gameController).GetComponent<HashIDs>();
 
         enemy = GameObject.FindGameObjectWithTag(Tags.enemy);
 
     }
 
     void Start() {
 
         spotted = false;
 
     }
 
     void Update(){
 
         Ray ray = Camera.main.ViewportPointToRay(new Vector3(0.5f, 0.5f, 0));
 
         RaycastHit hit;
 
         if(Physics.Raycast(ray, out hit, playerSightDistance)){
 
             if(hit.collider.gameObject == enemy){
                 spotted = true;
 
                 Debug.Log("Enemy spotted");
 
             }
             else
             {
                 spotted = false;
             }
 
         }
 
     }

Each enemy has a capsule collider for their physics collider and a sphere collider set to Is Trigger which represents their area of vision. They're all tagged Enemy. What could possibly make it so only one specific enemy is detected by the raycast?