[Bug]: Thumbnail toolbar buttons are removed when Explorer is restarted

[tr2-harada]

Preflight Checklist

• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for a bug report that matches the one I want to file, without success.

Electron Version

25.4.0

What operating system are you using?

Windows

Operating System Version

Windows 10 Pro 22H2 (19045.3324)

What arch are you using?

x64

Last Known Working Electron version

No response

Expected Behavior

After adding buttons with BrowserWindow.setThumbarButtons, thumbnail toolbar buttons persist across explorer restarts.

Actual Behavior

After adding buttons with BrowserWindow.setThumbarButtons, thumbnail toolbar buttons are removed when explorer is restarted.
After that, you can't add buttons with BrowserWindow.setThumbarButtons.

Testcase Gist URL

No response

Additional Information

You can restart Explorer by selecting the Explorer context menu from Task Manager.