Knock back force is not stopping

Hello everyone, I have been watching a Udemy course for building an FPS game. In the Knock back force section after I implemented it and tried to test it, The moment the player get hit the knock back effect never ends and the player keeps getting pushed away. What may be the problem??

the code for the Player:

using System.Collections; using System.Collections.Generic; using UnityEngine;

public class Player : MonoBehaviour {

 [Header("Visuals")]
 public Camera playerCamera;
 
 [Header("Gameplay")]
 public int initialHealth = 100;
 public int initialAmmo = 12;
 public float knockBackForce = 50;
 public float hurtDuration = 0.5f;
 private int health;
 public int Health { get {return health;} }
 
 private int ammo;
 public int Ammo { get { return ammo;} }
 
 private bool isHurt;
 // Start is called before the first frame update
 void Start()
 {
     ammo = initialAmmo;
     health = initialHealth;
 }

 // Update is called once per frame
 void Update()
 {
     if ( Input.GetMouseButtonDown(0)){
         if(ammo > 0){
             ammo--;        

             GameObject bulletObject = ObjectPoolingManager.Instance.GetBullet(true);
             bulletObject.transform.position = playerCamera.transform.position + playerCamera.transform.forward; //The bulletObject starting from the players position and with an offset
             bulletObject.transform.forward = playerCamera.transform.forward;
             }
     }
 }
 //check for collisions

 void OnTriggerEnter(Collider OtherCollider){
     
     if (OtherCollider.GetComponent<AmmoCrate>() != null){
         //Collect ammoCrate
         AmmoCrate ammoCrate  = OtherCollider.GetComponent<AmmoCrate>();
         ammo += ammoCrate.ammo;
         
         Destroy(ammoCrate.gameObject);
     }
     if (isHurt == false){
         
         GameObject hazard = null;
         if(OtherCollider.GetComponent<Enemy>() != null){
         //Collide with enemies

             
             Enemy enemy = OtherCollider.GetComponent<Enemy>();
             hazard = enemy.gameObject;
             health -= enemy.damage;
             

         }
         else if(OtherCollider.GetComponent<Bullet> () != null){
             Bullet bullet = OtherCollider.GetComponent<Bullet> ();
             if(bullet.ShotByPlayer  == false){
                 hazard = bullet.gameObject;
                 health -= bullet.damage;
                 bullet.gameObject.SetActive(false);
                 
             }
         }
         if (hazard != null){
             isHurt = true;
             //Perform the knock back effect
             Vector3 hurtDirection =  (transform.position - hazard.transform.position).normalized;
             Vector3 knockBackDirection = (hurtDirection + Vector3.up).normalized;
             GetComponent<ForceReceiver> ().AddForce(knockBackDirection, knockBackForce);
                      
             StartCoroutine (HurtRoutine());
         }
         
     }
     
 
 }
 
 IEnumerator HurtRoutine(){
     isHurt = false;
     yield return new WaitForSeconds (hurtDuration);
     
     
 }

}