Texture importer script: How to avoid resetting value when make changes

Hi everyone,

I want to change the default texture importer settings, so that the [Pixels to Units] = 1. After some research, I use this Editor script...

 using UnityEngine;
 using UnityEditor;
 
 public class ChangeImporterSetting : AssetPostprocessor
 {
     void OnPostprocessTexture(Texture2D texture)
     {
         TextureImporter importer = assetImporter as TextureImporter;
         importer.spritePixelsToUnits = 1;
 
         Object asset = AssetDatabase.LoadAssetAtPath(importer.assetPath, typeof(Texture2D));
         if (asset)
         {
             EditorUtility.SetDirty(asset);
         }
         else
         {
             importer.spritePixelsToUnits = 1;
         }
     }
 }

It’s work. When I add a texture, it's default [Pixels to Units] is 1.

The problem is that when I change the setting for some texture, then save the scene, the changed setting resets to default value. For example, I change "example.png" [Pixels to Units] = 2, then save the scene, "example.png" [Pixels to Units] reset back to 1.

Could you suggest some change to the code to resolve the said problem?
Thank you.