How to reproduce:
1. Create a new Unity project
2. Create any GameObject and add a child GameObject to it
3. Make sure to have the parent GameObject expanded
4. Click the three-dot menu -> UI Toolkit Live Reload
5. Observe the results

Expected results: The GameObject is not collapsed
Actual results: The GameObject becomes collapsed

Reproducible with: 6000.3.0a2, 6000.3.0a6
Can't test with: 6000.0.56f1, 6000.1.16f1, 6000.2.1f1, 6000.3.0a1 (Hierarchy V2 is not available) 

Reproducible on: macOS Sequoia 15.5 (M1)
Not reproducible on: No other environment tested

Notes:
- Reproducible both when toggling the UI Toolkit Live Reload on and off
- Doesn't reproduce in Hierarchy V1