Custom Inspector for ScriptableObject

Hello guys! I have some problem. Please help me.

This my ScriptableObject

     [System.Serializable]
     public class dm_MapTiles : ScriptableObject
     {
 
         public dm_MapTiles() { }
 
         public string mapName;
         public Sprite[,] mapSprites;
 
     }

And this is my Custom Editor Script

 using UnityEditor;
 using UnityEngine;
 using System.Collections.Generic;
 
 [CustomEditor(typeof(dm_MapTiles))]
 public class dm_MapTilesEditor : Editor {
 
     dm_MapTiles comp;
     static bool showTileEditor = false;
 
     public void OnEnable()
     {
         comp = (dm_MapTiles)target;
         if (comp.mapSprites == null)
         {
             comp.mapSprites = new Sprite[1,1];
         }
     }
 
     public override void OnInspectorGUI()
     {
 
         //MAP DEFAULT INFORMATION
         comp.mapName = EditorGUILayout.TextField("Name", comp.mapName);
 
         //WIDTH - HEIGHT
         int width = EditorGUILayout.IntField("Map Sprite Width", comp.mapSprites.GetLength(0));
         int height = EditorGUILayout.IntField("Map Sprite Height", comp.mapSprites.GetLength(1));
 
         if (width != comp.mapSprites.GetLength(0) || height != comp.mapSprites.GetLength(1))
         {
             comp.mapSprites = new Sprite[width, height];
         }
 
         showTileEditor = EditorGUILayout.Foldout(showTileEditor, "Tile Editor");
 
         if (showTileEditor)
         {
             for (int h = 0; h < height; h++)
             {
                 EditorGUILayout.BeginHorizontal();
                 for (int w = 0; w < width; w++)
                 {
                     comp.mapSprites[w, h] = (Sprite)EditorGUILayout.ObjectField(comp.mapSprites[w, h], typeof(Sprite), false, GUILayout.Width(65f), GUILayout.Height(65f));
                 }
                 EditorGUILayout.EndHorizontal();
             }
         }
     }
 
 }
 

And this my screenshot

If I Play game, my scriptableobject lost all data. Please help me.