Remap UVs and persist the changes

Hi,

I have a set of around 50 prefabs each one with its own LODs. I'm trying to remap the UVs of all the meshes to my atlas texture using a C# script in Unity because I don't want to make it one by one from Blender. I've done the code that makes de trick but I'm not able to persist the changes so when I close the Unity editor, next time I open it all the changes are lost.

I've tryed to execute this code at runtime on an instance of the prefab and Apply then the changes to update the prefab. Everything seems ok until I shut down the editor and open it again .

I've tryed to execute this code in Editor mode (not runtime) directly on the prefab (with an editor script and a button). Same as before: the remap seems ok but after shuting down Unity and opening it again all the changes are vanished.

Someone can give me an idea of what's going on?

Many thanks guys

PS: my remap code

  MeshFilter[] meshes = objecte.transform.GetComponentsInChildren<MeshFilter>();
  
 
         foreach (var m in meshes)
         {
            var mesh = m.sharedMesh;
             List<Vector2> uvs = new List<Vector2>();
             List<Vector2> newUvs = new List<Vector2>();
             mesh.GetUVs(0, uvs);
 
             for (int i = 0; i < uvs.Count; i++)
             {                
                 var v2 = new Vector2((uvs[i].x * factorEscalatX) + offsetX, (uvs[i].y * factorEscalatY) + offsetY);
                 newUvs.Add(v2);
             }
 
             mesh.SetUVs(0, newUvs);
         }
 
         //AssetDatabase.SaveAssets();  useless :(