Reproduction steps:
1. Open the attached “BugRepro” project
2. From the menu navigate to Test > SO Test
3. Notice the "My SO" property is “(My So)” in the SoTest window
4. Reopen the “Assets/Scenes/SampleScene.unity” Scene (double-click on Scene in the Project window)
5. Observe the "My SO" property in the SoTestWindow

Expected result: The "My SO" property should display as “(My SO)”
Actual result: The "My SO" property shows “Missing (Object)”

Reproducible with: 2021.3.44f1, 2022.3.52f1, 6000.0.27f1, 6000.1.0a4

Reproducible on: Windows 11
Not reproducible on: No other environment tested