How to reproduce:
1. Create a new Unity project
2. In the Project window, create the multiple scenes (right-click -> Create -> Scene -> Scene)
3. Drag and drop all scenes into the Hierarchy
4. Expand some scenes and collapse some scenes
5. Enter the Play Mode and observe the Hierarchy

Expected results: The structure remains the same all the time
Actual results: For a brief moment, collapsed scenes are expanded and expanded scenes are collapsed

Reproducible with: 6000.3.1f1, 6000.4.0b1, 6000.5.0a3
Can't test with: 6000.0.64f1, 6000.2.15f1 (No Hierarchy V2)

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

Note: Not reproducible in Hierarchy V1