iPhone 11 Face ID not working

Follow these steps, testing after each step:

• Face ID not working.
• Software Update.
• Turn iPhone on or off.
• Force Restart iPhone.

If that didn’t work, then it could be a hardware issue.

According to Apple:

Using diagnostics available in iOS 14.6 or later, Apple has detected an issue with your TrueDepth camera that might cause it to not function as expected. The TrueDepth camera contains lasers, which might be disabled for safety reasons if the device malfunctions or is damaged. This won't prevent you from using your iPhone or iPad, but until your iPhone or iPad is updated or serviced, you might not be able to use Face ID, Animoji, Memoji, and some other features that use the front camera.

As a result, I recommend service.

Service Checklist:

• iPhone service pricing.
• Check AppleCare Coverage.
• Get your iPhone ready for service.

Click ▶︎ Start a Repair Request.

Need more help?

• Call 1-800-APLCARE.
• Contact Support.
• iPhone Support.
• iPhone User Guide.

Click ▶︎ Check Repair Status. 🔧

Good luck! 👋🏼😉

Check this, If an alert says Face ID has an issue on your iPhone or iPad Pro - Apple Support and this, If Face ID isn't working on your iPhone or iPad Pro - Apple Support

There may be something wrong with your TrueDepth camera. Please view the following articles.

If Face ID isn't working on your iPhone or iPad Pro - Apple Support

If an alert says Face ID has an issue on your iPhone or iPad Pro - Apple Support

If the above doesn’t help, please make a reservation at your nearest Apple Store Genius Bar or Apple Authorized Service Provider for diagnostics.

Genius Bar Reservation and Apple Support Options - Apple