Tag in code only responds to 1 object.

I made a code to pick up some items and there are some mistakes .

1. Whatever item I try to pick up, it only responds to 1 item (if I try to pick up item 1 or 2, it always moves item 1).

2. Whenever I try to pick up the only item that moves from the first problem the gravity turns off like it should, but if I try to pick up another item the gravity doesn't turn off.

Any help is much appreciated.

 using UnityEngine;
 using System.Collections;
 
 public class PickUp : MonoBehaviour {
     
     // The variables for the positions.
         Offset to the character.
             float OffsetPositionX = 1;
             float OffsetPositionY = 1;
             float OffsetPositionZ = 1;
         // Relative position to the character.
             float CharacterPositionX;
             float CharacterPositionY;
             float CharacterPositionZ;
   
     // The Player and the tagged objects.
         public GameObject CarryableObject;
         public GameObject Character;
   
     void Start() {
         // The origin of the objects.
             CarryableObject = GameObject.FindWithTag("Carryable");
             Character = GameObject.Find("Character");
         // The code for determining the position (Put in note mode to deactivate but keep it).
             CharacterPositionX = Character.transform.position.x + OffsetPositionX;
             CharacterPositionY = Character.transform.position.y + OffsetPositionY;
             CharacterPositionZ = Character.transform.position.z + OffsetPositionZ;
   }
     
     void OnTriggerStay(Collider other) {
         if(Input.GetKeyDown("e")) {
             // The position relative to the character.
                 CarryableObject.transform.position = new Vector3(CharacterPositionX, CharacterPositionY, CharacterPositionZ);
             // The rotation relative to the character.
                 CarryableObject.transform.rotation = Character.transform.rotation;
         }
         if(Input.GetKeyDown("e")) {
             // The gravity.
                 other.attachedRigidbody.useGravity = false;
         }
     }
 }

The position the only moving item goes to:

Also, I think this might have something to do with the entire game and not just the code so here is a link to my game in the google drive. link to the game files