Drawing a cube by a new Mesh

Hi guys, I am with a very simple problem, but it is blocking my work. I am instantiating a cube with a new Mesh, setting manually all the vertices, uv's, triangles and normals. This is my code:

 using UnityEngine;
 using System.Collections;
 
 public class cube : MonoBehaviour {
     public Vector3 index;
     void Start(){
         mesh.Clear();
         mesh.vertices = new Vector3[] {new Vector3(0, 0, 0), new Vector3(0, 1, 0), new Vector3(1, 1, 0), new Vector3(1, 0, 0),  //front
                                        new Vector3(1, 0, 1), new Vector3(1, 1, 1), new Vector3(0, 1, 1), new Vector3(0, 0, 1),  //back
                                        new Vector3(1, 0, 0), new Vector3(1, 1, 0), new Vector3(1, 1, 1), new Vector3(1, 0, 1),  //right
                                        new Vector3(0, 0, 1), new Vector3(0, 1, 1), new Vector3(0, 1, 0), new Vector3(0, 0, 0),  //left
                                        new Vector3(0, 1, 0), new Vector3(0, 1, 1), new Vector3(1, 1, 1), new Vector3(1, 1, 0),  //top
                                        new Vector3(0, 0, 0), new Vector3(0, 0, 1), new Vector3(1, 0, 1), new Vector3(1, 0, 0)}; //bottom
         mesh.uv = new Vector2[] {new Vector2(0, 0),    new Vector2(0, 1),    new Vector2(1, 1),    new Vector2 (1, 0),
                                  new Vector2(0, 0),    new Vector2(0, 1),    new Vector2(1, 1),    new Vector2 (1, 0),
                                  new Vector2(0, 0),    new Vector2(0, 1),    new Vector2(1, 1),    new Vector2 (1, 0),
                                  new Vector2(0, 0),    new Vector2(0, 1),    new Vector2(1, 1),    new Vector2 (1, 0),
                                  new Vector2(0, 0),    new Vector2(0, 1),    new Vector2(1, 1),    new Vector2 (1, 0),
                                  new Vector2(0, 0),    new Vector2(0, 1),    new Vector2(1, 1),    new Vector2 (1, 0)};
         mesh.triangles = new int[] {0,1,2,0,2,3,4,5,6,4,6,7,8,9,10,8,10,11,12,13,14,12,14,15,16,17,18,16,18,19,20,21,22,20,22,23};
         mesh.normals = new Vector3[] {new Vector3( 0, 0,-1),new Vector3( 0, 0,-1),new Vector3( 0, 0,-1),new Vector3( 0, 0,-1),  //front
                                       new Vector3( 0, 0, 1),new Vector3( 0, 0, 1),new Vector3( 0, 0, 1),new Vector3( 0, 0, 1),  //back
                                       new Vector3( 1, 0, 0),new Vector3( 1, 0, 0),new Vector3( 1, 0, 0),new Vector3( 1, 0, 0),  //right
                                       new Vector3(-1, 0, 0),new Vector3(-1, 0, 0),new Vector3(-1, 0, 0),new Vector3(-1, 0, 0),  //left
                                       new Vector3( 0, 1, 0),new Vector3( 0, 1, 0),new Vector3( 0, 1, 0),new Vector3( 0, 1, 0),  //top
                                       new Vector3( 0,-1, 0),new Vector3( 0,-1, 0),new Vector3( 0,-1, 0),new Vector3( 0,-1, 0)}; //bottom
     }
 }

The problem is: the bottom face normals are inverted, and i can't invert them. This is the cube made by this code, with the normals drawn on Gizmos.

The normals settings are correct. This is the same cube, with only the bottom face drawn.

Then the normals are really bugged, not simply inverted. In the image1, the bottom normals are settled like the posted code. The image2 is the bottom normals with the inverted normals.

I don't know why it's happening. Please help me!! thanks!