When I try to use Animoji, I see "Tap to resume" When I try to use Animoji, I get the following message/error:


  Tap to resume


Additionally, when I tap on my Memoji, I get


  Face tracking failed. Tap to retry


However, tapping does not resolve the issue. I've also tried a hard reboot/force restart, resetting all settings, and erasing the phone and resetting all settings—and none of those fixed the problem.

Face ID seems completely unaffected.

What can I do to fix this?
Today, I went back to the Apple Store.

After running some tests, they were able to determine a problem with the telephoto lens and Face ID. (Curiously, they saw someone with the same problem earlier that day.)

Because my phone was still within its warranty period, they replaced it free of charge.

Your mileage may vary, but it's worth a shot!