Reproduction steps:
1. Open the “BugReport_NestedManagedReference” project
2. Open the “SampleScene” scene
3. In the Hierarchy Window select “TestPrefab” Game Object
4. Click the “Overwrite ManagedReference” button in the Inspector Window
5. Rightclick on the "My Inner Class" foldout and select "Apply to Prefab ‘TestPrefab’"
Expected results: A warning is shown preventing to perform the action
Actual results: No warning is shown and the underlying field "Inner Int" disappears from the Inspector Window
Reproducible with: 2021.3.16f1, 2022.2.2f1, 2023.1.0a26
Could not test with: 2020.3.44f1 (com.unity.feature.development: Package [com.unity.feature.development@1.0.1] cannot be found)
Reproduced on: Intel MacOS 13.1