RenderSettings.skybox script edit does not work

I wrote this little script to change the skybox anytime the player interacts with a series of objects, but it does not work, usually the first time I use it works perfectly, the second time it doesn't change anything anymore. And when I export it the build does not do it. Here's the script:

 using UnityEngine;
 using System.Collections;
 
 public class SkyboxBugger : MonoBehaviour {
     
     public Material Down;
     public Material Sunny;
     public Material Night;
     
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
         
                 RaycastHit hit;
         Ray ray = Camera.main.ScreenPointToRay(new Vector3(Screen.width/2, Screen.height/2, 0));
         
         
         if(Physics.Raycast(ray, out hit, 2))
         {
             if(hit.collider.tag == "Buya")  
             {
                 if( Input.GetButton ("Fire1") ) {
                     
                 //Change skybox
                     RenderSettings.skybox = Down;
                 }
             }
             if(hit.collider.tag == "Computer")  
             {
                 if( Input.GetButton ("Fire1") ) {
                     
                 //Change skybox
                     RenderSettings.skybox = Sunny;
                 }
             }
             if(hit.collider.tag == "JoyStation")  
             {
                 if( Input.GetButton ("Fire1") ) {
                     
                 //Change skybox
                     RenderSettings.skybox = Night;
                 }
             }
             
         }
     
     }
 }