Property drawer with multiple fields: only first field has prefab override implemented

Hey guys:

I've been trying to just make a custom property drawer for a serializeable class with multiple fields. It works fine, the problem is just when I try use it on a prefab and I try to override some (not all) of it's values on a instance. The label simply does not go bold, indicating that it is overriding over the prefab.

When I change the enemy_alert AudioClip value, the property label get bold. It doesn't when I change the enum or the bool.

Am I doing something wrong?

Here's my code:

 public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
     {
         EditorGUI.BeginProperty(position, label, property);
 
         int indent = EditorGUI.indentLevel;
         EditorGUI.indentLevel = 0;
         
         SerializedProperty sound = property.FindPropertyRelative("sound");
         SerializedProperty source = property.FindPropertyRelative("source");
         SerializedProperty hasMoreSounds = property.FindPropertyRelative("moreSounds");
         SerializedProperty randomSounds = property.FindPropertyRelative("sfxRandomSounds");
 
         Rect col = position;
 
         col.width = position.width * 0.7f;
         Rect soundRect = col;
         EditorGUI.PropertyField(soundRect, sound, label);
 
         col.x += col.width;
         col.width = position.width * 0.3f - 10f;
         EditorGUI.PropertyField(col, source, GUIContent.none);
 
         col.x += col.width;
         col.width = position.width * 0.1f;
         EditorGUI.PropertyField(col, hasMoreSounds, GUIContent.none);
 
 
         if (hasMoreSounds.boolValue)
         {
             EditorGUI.indentLevel++;
             EditorGUI.BeginChangeCheck();
             EditorGUILayout.PropertyField(randomSounds, true);
             if (EditorGUI.EndChangeCheck())
                 property.serializedObject.ApplyModifiedProperties();
             EditorGUI.indentLevel--;
         }
 
         EditorGUI.indentLevel = indent;
 
         EditorGUI.EndProperty();
     }