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

24.4.0

What operating system are you using?

Windows

Operating System Version

Windows 11 version 22H2 build 22624.1755

What arch are you using?

x64

Last Known Working Electron version

No response

Expected Behavior

When setting the backgroundMaterial property on a new BrowserWindow, it is expected for the window background to use the material as well as the titlebar.

Actual Behavior

Only the titlebar of the window has the material, but the client area remains white or any other background color, unless the window is set to be transparent (see below).

Testcase Gist URL

No response

Additional Information

You can work around this issue by setting transparent: true, show: false in the window constructor, and showing the window after the webcontents have been loaded. But this approach raises and issue: the window becomes unresizeable and the thickFrame: true option is ignored. The method window.setResizeable(true) doesn't work either.