Steps to reproduce:

1. Create a new URP project
2. Open Preferences window
3. Navigate to General tab
4. Under "New Hierarchy", enable (or disable) "Use new Hierarchy window" property
5. Observe the Preferences window

Actual results: Preferences window automatically closes

Expected results: Preferences window remains open

Reproducible with versions: 6000.3.13f1, 6000.4.4f1, 6000.5.0b6, 6000.6.0a4

Can’t test with versions: 6000.0.73f1 (Hierarchy V2 not available)

Tested on (OS): macOS 26.4

Notes:

• Does not reproduce on Windows 11 and Ubuntu 24.04
• The window does not close, but loses focus and on Mac, it puts it behind the focused window (see attached video). This is not technically a bug, but it's annoying. I'm keeping it open only because it's HV2 and we want maximum polish on release, but this is really a non-issue. -[~sebastienlh]