News Microsoft has broken Windows Hello facial recognition — it no longer works in the dark

The horror of having to type 123456789!

But really since Windows Hello allows multiple concurrent login methods (face, PIN, fingerprint, security key), use your insecure face during the day and a much more secure PIN at night.
 
I use aTobi eye tracker for Hello, I wouldn't even have known about this change happening if it were not for Tom's. Signing in in the dark still works fine as far as I can tell, but it is good to know what the problem might be if it stops.

Also found a good explanation of the problem on Windowsforum here