Prefab destroyed upon instantiation

Hi everybody, first question here, hope it's a good one!

I'm creating a game where the player gets multiple weapons they can swap between. To facilitate this, I have created a base class (WeaponBase) and inheriting from that, a child class (WeaponSword).

WeaponSword looks like this (pared down to relevant code only):

     public class WeaponSword : WeaponBase
     {
         // Use this for initialization
         void Start()
         {
             print("Sword Start");
         }
 
         void OnDestroy()
         {
             Debug.Log("Sword Destroyed");
         }
 
         // Update is called once per frame
         void Update()
         {
             Debug.Log("Sword Update");
         }
     }
 }

I've created a Prefab which has my sword model, animations, etc, and the WeaponSword script.

I have created a GameObject in the scene to which a script is attached to handle the weapons, and this script has a public array (weapons) which stores my list of weapons. I've dragged the Prefab into the script's weapons slot in the Unity Editor.

Here is the relevant code:

         public GameObject[] weapons;
 
         private GameObject equippedWeapon;
 
         // Use this for initialization
         void Start()
         {
             equippedWeapon = (GameObject)Instantiate(weapons[0]);
         }

     void Update()
     {
         Debug.Log(equippedWeapon);
     }

Here is where it gets tricky...

When I start the game, the weapon's model does not appear. If I pause the game and investigate the Scene view and look at the list of GameObjects, I do not see any WeaponSword objects... Looking at the console, I see some very strange behavior. The logs look like this:

 Sword Start
 WeaponSword(Clone) (UnityEngine.GameObject)
 Sword Update
 WeaponSword(Clone) (UnityEngine.GameObject)
 Sword Start
 Sword Update
 Sword Start
 Sword Destroyed
 Sword Destroyed
 Sword Destroyed
 null
 null
 null
 null

so what I gather from that is that... apparently multiple copies of this Prefab are instantiated (despite existing only as a Prefab and not in the scene initially, and the only call to instantiate is the one in the weapon management script which exists only once in the scene), then all of them are deleted (actually, all of them are deleted and then one more that does not apparently Start is Destroyed as well!), and from then on my weapon manager script stores no reference to the object.

I don't call Destroy anywhere in this code, and especially do not call Destroy on any WeaponSword objects.

Why is my instantiated object getting destroyed immediately?

Thank you for reading this rather long and involved question.