Question ColorAdjustsments volume override is missing settings after restart

I noticed that in one of my script-created volume profiles the settings for the ColorAdjustments override are missing after I restart Unity (2021.1.22).

It looks like the settings go missing unless at least one of a few specific overrides are present as well. I can't tell what's special about them. For example adding Fog works, but adding ScreenSpaceReflection does not.

Is there a reason for this? I'd appreciate it if someone could test the script below and tell me if it's reproducible.

• Add script to Assets/Scritps/Editor
• Go to "Window ➜ VolumeProfileTest" and click "Create"
  
• Don't change anything in the volume profiles
  
• Restart Unity
• VolumeProfile1.asset should be missing its "Color Adjustments ➜ Post Exposure" setting
• VolumeProfile2.asset should still have it

Code (CSharp):

1. using UnityEditor;
2. using UnityEditor.Rendering;
3. using UnityEngine;
4. using UnityEngine.Rendering.HighDefinition;
5.  
6. public class Window : EditorWindow
7. {
8.     [MenuItem("Window/VolumeProfileTest")]
9.     public static void ShowWindow()
10.     {
11.         GetWindow<Window>("VolumeProfileTest");
12.     }
13.  
14.     private void OnGUI()
15.     {
16.         if (GUILayout.Button("Create")) {
17.             CreateVolumeProfile1();
18.             CreateVolumeProfile2();
19.         }
20.     }
21.  
22.     private void CreateVolumeProfile1()
23.     {
24.         var volumeProfile1 = VolumeProfileFactory.CreateVolumeProfileAtPath("Assets/VolumeProfile1.asset");
25.  
26.         var colorAdjustments = VolumeProfileFactory.CreateVolumeComponent<ColorAdjustments>(volumeProfile1);
27.  
28.         // Missing after restart
29.         colorAdjustments.postExposure.overrideState = true;
30.         colorAdjustments.postExposure.value = 2;
31.     }
32.  
33.     private void CreateVolumeProfile2()
34.     {
35.         var volumeProfile2 = VolumeProfileFactory.CreateVolumeProfileAtPath("Assets/VolumeProfile2.asset");
36.  
37.         // "Bugfix"
38.         VolumeProfileFactory.CreateVolumeComponent<Fog>(volumeProfile2);
39.  
40.         var colorAdjustments = VolumeProfileFactory.CreateVolumeComponent<ColorAdjustments>(volumeProfile2);
41.  
42.         // Remain after restart
43.         colorAdjustments.postExposure.overrideState = true;
44.         colorAdjustments.postExposure.value = 2;
45.     }
46. }