PanelRenderer ignores Transform.SetParent changes when initial UI creation is complete

How to reproduce:

1. Open the attached “IN-154554“ project
2. Enter Play mode
3. Observe the Console window

Actual result: The first and second test’s fail (Full actual logs in internal notes)
Expected result: All three test’s pass (Full expected logs in internal notes)

Reproducible with: 6000.6.0a1, 6000.6.3f1, 6000.7.0b2, 7000.0.0a1
Could not test with: 6000.0.0f1, 6000.0.84f1, 6000.3.25f1 (Couldn’t safely downgrade the project)

Reproducible on: Windows 10 (by user), Windows 11
Not reproducible on: No other environment tested