Question Transform 2D array losing reference on 'Play'

This image is the Scriptable Object that I am trying to store a 2D array of Transforms, but whenever I press 'Play' or update the script/editor all the references get lost




I am serializing my custom class on the ScriptableObject, but it just don't work :/
2D Array really can't be serialized?


Scriptable Object code:

Code (CSharp):

1. using UnityEngine;
2.  
3. [CreateAssetMenu(fileName = "Game Settings", menuName = "ScriptableObjects/Game Settings", order = 1)]
4. public class GameSettings : ScriptableObject
5. {
6.     public Level level;
7. }
8.  
9. [System.Serializable]
10. public class Level
11. {
12.     public Transform[,] spawnPoints = new Transform[4, 4];
13. }

Editor code:

Code (CSharp):

1.  
2. using System;
3. using UnityEngine;
4. using UnityEditor;
5.  
6. [CustomEditor(typeof(GameSettings))]
7. public class GameSettingsEditor : Editor
8. {
9.     public override void OnInspectorGUI()
10.     {
11.         GameSettings settings = (GameSettings)target;
12.         EditorGUILayout.Space();
13.  
14.         EditorGUI.indentLevel++;
15.  
16.  
17.         EditorGUI.indentLevel = 0;
18.  
19.         GUIStyle tableStyle = new GUIStyle("box");
20.         tableStyle.padding = new RectOffset(20, 20, 20, 20);
21.         tableStyle.margin.left = 12;
22.  
23.         GUIStyle headerColumnStyle = new GUIStyle();
24.         headerColumnStyle.fixedWidth = 65;
25.  
26.         GUIStyle columnStyle = new GUIStyle();
27.         columnStyle.fixedWidth = 120;
28.  
29.         GUIStyle rowStyle = new GUIStyle();
30.         rowStyle.fixedHeight = 70;
31.  
32.         GUIStyle rowHeaderStyle = new GUIStyle();
33.         rowHeaderStyle.fixedWidth = columnStyle.fixedWidth - 1;
34.  
35.         GUIStyle columnHeaderStyle = new GUIStyle();
36.         columnHeaderStyle.fixedWidth = 80;
37.         columnHeaderStyle.fixedHeight = 70;
38.  
39.         GUIStyle columnLabelStyle = new GUIStyle();
40.         columnLabelStyle.fixedWidth = rowHeaderStyle.fixedWidth - 6;
41.         columnLabelStyle.alignment = TextAnchor.MiddleCenter;
42.         columnLabelStyle.fontStyle = FontStyle.Bold;
43.  
44.         GUIStyle cornerLabelStyle = new GUIStyle();
45.         cornerLabelStyle.fixedWidth = 42;
46.         cornerLabelStyle.alignment = TextAnchor.MiddleRight;
47.         cornerLabelStyle.fontStyle = FontStyle.BoldAndItalic;
48.         cornerLabelStyle.fontSize = 14;
49.         cornerLabelStyle.padding.top = -5;
50.  
51.         GUIStyle headerStyle = new GUIStyle();
52.         headerStyle.fixedWidth = 80;
53.         headerStyle.alignment = TextAnchor.MiddleCenter;
54.         headerStyle.fontStyle = FontStyle.BoldAndItalic;
55.         headerStyle.fontSize = 14;
56.         headerStyle.padding.top = -40;
57.         headerStyle.padding.left = 120;
58.  
59.         GUIStyle rowLabelStyle = new GUIStyle();
60.         rowLabelStyle.fixedWidth = 25;
61.         rowLabelStyle.alignment = TextAnchor.MiddleRight;
62.         rowLabelStyle.fontStyle = FontStyle.Bold;
63.         rowStyle.fixedWidth = 110;
64.  
65.         EditorGUILayout.BeginHorizontal(tableStyle);
66.         for (int x = -1; x < 4; x++)
67.         {
68.             EditorGUILayout.BeginVertical((x == -1) ? headerColumnStyle : columnStyle);
69.             for (int y = -1; y < 4; y++)
70.             {
71.                 if (x == -1 && y == -1)
72.                 {
73.                     EditorGUILayout.BeginVertical(rowHeaderStyle);
74.                     EditorGUILayout.LabelField("[X,Y]  Note spawn positions", headerStyle);
75.                     EditorGUILayout.EndHorizontal();
76.                 }
77.                 else if (x == -1)
78.                 {
79.                     EditorGUILayout.BeginVertical(columnHeaderStyle);
80.                     EditorGUILayout.LabelField(y.ToString(), rowLabelStyle);
81.                     EditorGUILayout.EndHorizontal();
82.                 }
83.                 else if (y == -1)
84.                 {
85.                     EditorGUILayout.BeginVertical(rowHeaderStyle);
86.                     EditorGUILayout.LabelField(x.ToString(), columnLabelStyle);
87.                     EditorGUILayout.EndHorizontal();
88.                 }
89.  
90.                 if (x >= 0 && y >= 0)
91.                 {
92.                     EditorGUILayout.BeginHorizontal(rowStyle);
93.              
94.                     settings.level.spawnPoints[x, y] = (Transform)EditorGUILayout.ObjectField(settings.level.spawnPoints[x, y], typeof(Transform), true);
95.                     EditorGUILayout.EndHorizontal();
96.                 }
97.             }
98.             EditorGUILayout.EndVertical();
99.         }
100.         EditorGUILayout.EndHorizontal();
101.  
102.     }
103. }
104.  
105.