Reproduction steps:
1. Open the attached project "ReproProj"
2. Open the “/Assets/Scenes/SampleScene.unity” Scene
3. Enter the Play Mode
4. In the Project window, create a new C# Script (Right-click > Create > C# Script)
5. Enter the Play Mode
6. Observe the Game and Scene views

Expected result: Simulated Environment Scene is present
Actual result: Simulated Environment Scene does not exist

Reproducible with: 5.1.1 (2021.3.35f1), 5.1.2 (2022.3.20f1), 6.0.0-pre.5 (2023.2.11f1), 6.0.0-pre.6 (2023.3.0b8)

Reproducible on: Windows 10 Enterprise 21H2
Not reproducible on: No other environment tested

Note:
- Reproducible in Play Mode with Windows and Android Platforms