I recently got a clean shave, and since then Face ID hasn't recognized me at all. I tried resetting Face ID and adding an alternate appearance, but both options require Face ID authentication. I also can't disable Stolen Device Protection because that requires Face ID too. It feels like I've locked myself out of my own iPhone just by changing my appearance. Is there anything I can try before erasing and restoring the phone?
2 Answers
Face ID normally adapts to gradual changes in appearance, but a major change like shaving off a full beard can prevent it from recognizing you. Try restarting the phone and carefully cleaning the Face ID sensors near the top of the display. If it still won’t recognize you, you may need to enter your passcode so Face ID can update its appearance data.
With Stolen Device Protection enabled, changing Face ID settings or turning the protection off may require successful Face ID authentication. If it continues to fail completely, the remaining option may be to back up the iPhone and erase it, using Finder on a Mac or the Apple Devices app on Windows, then restore it from your backup. Before doing that, make sure you can access important accounts—especially email and your password manager—from another device.

That update may not happen if the change is too drastic and Face ID never successfully recognizes you.