How to reproduce:
1. Create a new project
2. In the Package Manager, install the “Web Stripping Tool” package
3. In the menu bar, select “Window → Web Optimization → Submodule Stripping”
4. In the Submodule Stripping window, enable “Strip Automatically After Build”
5. Press “Select Submodules” and select “2D Rendering”
6. Restart the Editor
7. Observe the Stripping Settings in the Submodule Stripping window

Actual result: Submodule Stripping Settings are not saved between Editor sessions
Expected result: Submodule Stripping Settings are saved between Editor sessions

Reproducible with: 1.0.0 (6000.2.0a1), 1.2.1 (6000.6.0a1)

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Note: Issue also occurs when editing the Submodule Stripping Settings asset in the Inspector