Turn off Face ID

Please refer to Use Face ID on your iPhone or iPad Pro - Apple Support which states:

"To turn this feature on or off, go to Settings > Face ID & Passcode, then tap iPhone Unlock or iPad Unlock."

See the following from Set up Face ID on iPhone - Apple Support

Turn off Face ID

1. Go to Settings  > Face ID & Passcode.
2. Do one of the following:

• • Turn off Face ID for specific items only: Turn off one or more options: iPhone Unlock, Apple Pay, iTunes & App Store, or Safari AutoFill.
  • Turn off Face ID: Tap Reset Face ID.

Try a Force Restart for your iPhone.