Problem starting the game with a key

Hello everyone, I have a problem. I created a script so that my game would start when I pressed the X key and everything was fine, but I don't know what moved it and now it doesn't work, the game simply starts when I press play, I already checked the code and I see it. ok as it is supposed to work if someone can help me i appreciate it

This is my code

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

public class GameManager : MonoBehaviour { public GameObject menuPrincipal; public GameObject menuGameOver;

 public float velocidad = 2;
 public GameObject col;
 public GameObject piedra1;
 public GameObject aleteo;
 public GameObject aleteo2;
 public Renderer fondo;
 public bool gameOver = false;
 public bool start = false;

 public List<GameObject> cols;
 public List<GameObject> obstaculos;
 public List<GameObject> volador;
 // Start is called before the first frame update
 void Start()
 {
     // Crear Mapa
     for (int i = 0; i < 21; i++)
     {
         cols.Add(Instantiate(col, new Vector2(-8 + i, -5), Quaternion.identity));
     }

     // Crear Piedras
     obstaculos.Add(Instantiate(piedra1, new Vector2(-3, -3), Quaternion.identity));
     obstaculos.Add(Instantiate(aleteo, new Vector2(5, -3), Quaternion.identity));
     volador.Add(Instantiate(aleteo2, new Vector2(14, -1.6f), Quaternion.identity));
 }

 // Update is called once per frame
 void Update()
 {
     if (start == false) 
     {
     if (Input.GetKeyDown(KeyCode.X)) 
         {
             start = true;
         }
     }

     if (start == true && gameOver == true)
     {
         menuGameOver.SetActive(true);
         if (Input.GetKeyDown(KeyCode.X))
         {
             SceneManager.LoadScene(SceneManager.GetActiveScene().name);
         }
     }

     if (start == true && gameOver == false) 
     {
         menuPrincipal.SetActive(false);
         fondo.material.mainTextureOffset = fondo.material.mainTextureOffset + new Vector2(0.05f, 0) * Time.deltaTime;

         // Mover Mapa
         for (int i = 0; i < cols.Count; i++)
         {
             if (cols[i].transform.position.x <= -10)
             {
                 cols[i].transform.position = new Vector3(10, -5, 0);
             }
             cols[i].transform.position = cols[i].transform.position + new Vector3(-1, 0, 0) * Time.deltaTime * velocidad;
         }
         // Mover Obstaculos
         for (int i = 0; i < obstaculos.Count; i++)
         {
             if (obstaculos[i].transform.position.x <= -10)
             {
                 float randomObs = Random.Range(11, 18);
                 obstaculos[i].transform.position = new Vector3(randomObs, -3, 0);
             }
             obstaculos[i].transform.position = obstaculos[i].transform.position + new Vector3(-1, 0, 0) * Time.deltaTime * velocidad;

         }
         for (int i = 0; i < volador.Count; i++)
         {
             if (volador[i].transform.position.x <= -10)
             {
                 float randomObs = Random.Range(11, 18);
                 volador[i].transform.position = new Vector3(randomObs, -1.6f, 0);
             }
             volador[i].transform.position = volador[i].transform.position + new Vector3(-1, 0, 0) * Time.deltaTime * velocidad;

         }
     }
 }  

}