Fix an issue
If you're having trouble getting the phone to recognize your face:
1. Go to Settings > Security > Face Unlock.
2. Unlock your phone, then tap Redo face scan.
3. Be sure you are in a well lit environment. Avoid low light, strong light, and backlit environments to
ensure the face image is clear.
4. Follow the onscreen instructions.
Settings : Security : Lock and unlock phone 247