Issue Description
Face ID fails to unlock iPhone or authenticate apps.
Common Causes
Face obstruction
Disabled Face ID settings
iOS glitch
Step-by-Step Solution
Step 1: Check Face ID Settings
Settings → Face ID & Passcode
Ensure Face ID is enabled for unlock and apps
Step 2: Clean Front Camera
Remove dirt or screen protector blocking sensor
Step 3: Restart iPhone
Refreshes Face ID services
Step 4: Reset Face ID
Face ID & Passcode → Reset Face ID
Set up again
Explore Further
Update iOS if Face ID remains unreliable
Prevention & Best Practices
Avoid covering Face ID sensors.