Private fields disappear in the Inspector window when entering Play mode if the Inspector window mode is “Debug”

How to reproduce:
1. Open the attached “Debug.zip” project
2. Open the “SampleScene” Scene
3. In the Inspector window press three dots at the top right and choose “Debug”
4. Select “GameObject” GameObject and observe the script component fields
5. Enter Play Mode and observe the script component fields

Expected result: Fields are still visible
Actual result: Fields become not visible and “InvalidOperationException“ or “NullReferenceException“ errors appear

Reproducible with: 2022.2.0a9, 2022.2.0f1, 2023.1.0a21
Not reproducible with: 2020.3.42f1, 2021.3.15f1, 2022.1.23f1, 2022.2.0a8

Reproduced on:
macOS 12.4 (Intel)
Windows 10 Pro

Notes:

• fields become visible after deselecting and selecting the “GameObject” GameObject
• not reproducible with public fields