Why more balls are instantiating?

Hi, I'm making a game in unity where the user drags to shoot a ball at some objects at a distance. So far I have this DragAndShoot script:

 //using System.Collections;
 //using System.Collections.Generic;
 using UnityEngine;
 
 [RequireComponent(typeof(Rigidbody))]
 [RequireComponent(typeof(Collider))]
 public class DragAndShoot : MonoBehaviour
 {
     public Transform prefab;
     private Vector3 mousePressDownPos;
     private Vector3 mouseReleasePos;
 
     private Rigidbody rb;
 
     private bool isShoot;
     private bool ballShot;
   //  private int numChances = 3;
     
     void Start()
     {
         rb = GetComponent<Rigidbody>();
     }
 
     private void OnMouseDown()
     {
         mousePressDownPos = Input.mousePosition;
     }
 
     private void OnMouseUp()
     {
         mouseReleasePos = Input.mousePosition;
         Shoot(mouseReleasePos-mousePressDownPos);
     }
 
     private float forceMultiplier = 3;
     void Shoot(Vector3 Force)
     {
         if(isShoot)    
             return;
         
         rb.AddForce(new Vector3(Force.y,Force.x,Force.z) * forceMultiplier);
         isShoot = true;
         //ballShot = true;
         createBall();
     }
 
     void createBall(){
        // if (numChances > 0){
           //  numChances--;
         Instantiate(prefab, GameObject.Find("SpawnPoint").transform.position, Quaternion.identity);
        // }
     }
     
 }

As you can see, I made the function createBall() in order to respawn a ball prefab at the position of the game object SpawnPoint. When I run the game, the first ball shoots fine. And another ball respawns.

Issue: when I shoot the second ball and it moves, one more ball seems to have appeared at the second ball somehow, and it moves as well. I commented out the numChances variable and condition, but this still persists - another ball appears and moves with the second ball. Can someone pls help? Thanks.