A recent Windows update has changed how Windows Hello face unlock works, now requiring a color camera in addition to IR sensors to authenticate you. That means it can no longer see you in low-light environments.| Windows Central
Microsoft tweaked Windows Hello's biometric recognition to use your PC's optical webcam to "see" you, meaning that some users report that it's stopped working in the dark. To me, this is not a big deal.| PCWorld
Known issues in this update| support.microsoft.com
| msrc.microsoft.com