It happens to me on Windows 10 if I close the laptop lid to lock the desktop and send it to sleep.

When I open it again, the desktop is accessible for a few seconds (sometimes long enough to launch programs) before the lock screen activates and I have to input my password. The workaround I use is to manually lock with Win+L before closing the lid.

Would you mind posting a video? I have never seen this occurring in any version of Windows.

I tried a few times but it cannot be reliably reproduced. It successfully locked every time I tried today.

Windows have multiple desktop sessions(the normal user session, and the safe desktop). Even if you ever able to crash the one that host lock screen without bsod. You still won't be able to go back to the normal desktop.