Why when I try my game on android does not send me to the scenes I want?

I have this code:

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

public class intro : MonoBehaviour {

// Use this for initialization
void Update () {
    StartCoroutine ("returne");
}
public IEnumerator returne(){
    yield return new WaitForSeconds (3.06f);
    SceneManager.LoadScene ("main");
}


}
  

 I practically make 3.06f pass to the other scene, in unity all good and when I compile it to pc too, but when it comes to compiling and testing on android it does not load me, it stays with me, the same happens when I want to press a button to enter another scene, help please