The “lockscreen shadowbox” bug is a known issue in Windows 11 that affects the lock screen background image. The bug causes a black shadow box to appear on the lock screen, obscuring parts of the background image.
Lockscreen Shadowbox bug in Windows 11:
There are a few possible solutions to this problem:
Restart your PC: This is the simplest solution, and can often fix the problem without any further action.
Change the lock screen background: You can try changing the lock screen background to a different image. This may fix the problem, or at least reduce the visibility of the shadow box.
Update your graphics driver: The shadow box issue could be related to an outdated graphics driver. Updating your graphics driver may fix the problem.
Perform a clean boot: If none of the above solutions work, you can try performing a clean boot on your PC. This will start your PC with a minimal set of drivers and startup programs, which can help identify if a third-party software or service is causing the issue.
Check for windows update: You can also check for any available updates for your Windows 11, as Microsoft might have released an update that addresses the issue.
It’s important to note that if you are using a third-party theme or customization software that modifies the lock screen, this may be the cause of the issue. In this case, it may be necessary to uninstall or disable the software to fix the problem.
Direct download link for Windows 11 KB5022360