Reproduction steps:

1. Create a new project
2. Create a new GameObject in the Hierarchy
3. Create another GameObject by right-clicking on a parent
4. Follow step 3 again
5. Observe the result

Expected result: A child GameObject is created inside the selected parent GameObject by right clicking
Actual result: A child GameObject is created inside a last GameObject in the Hierarchy

Reproducible in: 6000.0.8f1 6000.0.35f1, 6000.1.0b3
Not reproducible in: 2022.3.56, 6000.0.7f1

Reproducible on: macOS 15.2 (M1 Pro), Windows 11
Not reproducible on: No other environments tested