Game slows down after restart

Hello guys, i got a runner game and my player dies when it collides with an obstacle.I made a slow motion after the collision to make the game cooler. On the game over screen i got restart button and after i press it game starts again but the time is still slow. I couldn't solve the issue please help me. There is my slow-motion code

 using UnityEngine;
 
 public class TimeManager : MonoBehaviour
 {
     public float slowdownFactor = 0.05f;
     public float slowdownLength = 4f;
     
     private void Update()
     {
         Time.timeScale += (1f / slowdownLength) * Time.unscaledDeltaTime;
         Time.timeScale = Mathf.Clamp(Time.timeScale, 0f, 1f);
     }
     
 
     public void DoSlowMotion()
     {
         Time.timeScale = slowdownFactor;
         Time.fixedDeltaTime = Time.timeScale * .02f;
         
     }
 
     
 }
 

and there is my Restart code

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.SceneManagement;
 using UnityEngine.UI;
 
 public class Restart : MonoBehaviour
 {
       
     public void RestartGame()
     {
 
         SceneManager.LoadScene("Level01");
 
     }
     
     
 }

and finally the collision code

  void OnCollisionEnter (Collision collisionInfo)
     {
         if (collisionInfo.collider.tag == "Obstacle")
         {
             movement.enabled = false;
             audioSource.pitch = speed;
             timeManager.DoSlowMotion();
             FindObjectOfType<GameManager>().gameOver();
             FindObjectOfType<GameManager>().EndGame();
             CountTime();
            
         }
     }