Setting a Default Parent in Scene marks all Hierarchy objects in bold

Steps to reproduce:

1. Open the attached project
2. Open the TestScene
3. Select the "GameObject"
4. Right-Click and Set as Default Parent
5. Observe objects in the Hierarchy window

Actual results: All objects in the Hierarchy are marked in bold

Expected results: Only the Default Parent object is marked in bold

Reproducible with versions: 6000.3.0a1, 6000.3.0a6

Not reproducible with versions: 2022.3.66f1, 6000.0.56f1, 6000.2.2f1

Tested on (OS): macOS 15.6.1

Notes:

• Even though all objects are marked in bold, newly created objects are placed under the correct Default Parent object
• Does not affect Hierarchy V2