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();
           
        }
    }

Reset Time.timeScale to 1 when you reload the scene.