Steps to reproduce:
1. Open the attached “workbench-dots.zip” project
2. Open the “SampleScene”
3. Open “Assets/WorldEditor/WorldEditorUI.uxml”
4. Expand the “ToggleButtonGroup”
5. Add a button as a child of “ToggleButtonGroup”
6. Right-click the “Button” and select Duplicate
7. Observe the Hierarchy Window

Expected result: The original Button stays child of “ToggleButtonGroup”
Actual result: The original Button is set to not a child of “ToggleButtonGroup”

Reproducible in: 6000.0.20f1, 6000.0.22f1
Not reproducible in: 6000.0.19f1
Couldn’t test in 2021.3.44f1, 2022.3.50f1 (ToggleButtonGroup did not exist in those versions)

Reproducible on: Windows 11, macOS(Silicon)
Not reproducible on: No other environment tested