Copy&paste from someone else
(thanks really much - worked on my 13 pro max)
Turns out, the problem was with content restrictions. I had content and privacy restrictions enabled, which were blocking Face ID from working properly. Here's how I fixed it:
- Go to Settings > Screen Time.
- Tap on Content & Privacy Restrictions.
- Enter your Screen Time passcode if prompted.
- Tap on Passcode Changes and set it to Allow.
- After turning off the restriction, Face ID started working again. So, before diving into software or hardware fixes, l'd recommend checking your this settings first.