Editor Reorderable List - Properties

Hello,

I'm trying to build a very simple Reorderable List of type GameObject, but I can't get my head around it, in my script of MonoBehaviour, I have a list:

 public List<GameObject> MyGameObjects = new List<GameObject>();

And within my Editor script (typeof above script):

 private ReorderableList _list;
 
 private void OnEnable() {
         _list = new ReorderableList(
         serializedObject, 
         serializedObject.FindProperty("MyGameObjects"), 
         true, true, true, true);
 
         _list.drawElementCallback = (Rect rect, 
         int index, 
         bool isActive, 
         bool isFocused) => {
         var element = _list.serializedProperty.GetArrayElementAtIndex(index);

         EditorGUI.PropertyField(new Rect(rect.x, 
             rect.y, 60, EditorGUIUtility.singleLineHeight),

             element.FindPropertyRelative("GameObject"));
     };
     }

The problem lies within 'FindPropertyRelative' I believe. This gives me the error: Object reference not set to an instance of an object?

Thanks.