I had the same problem and had to search a while for a solution that worked. It's crazy that Microsoft dares to release such a feature in this state.
Anyway, the solution I found goes as follows.
- From the lock screen. Click on Restart while holding shift.
- Go to Troubleshoot > System Restore
- A window should open where (hopefully) a version of windows will be shown from before you locked your pc. Reverting to this should "unlock" your pc (you still need to unlock the normal way) and you don't lose your files or apps.
Hope this helps! I'm not a computer expert so don't think that I can help any further. Good luck!