Face ID is not working after updating IOS 16

If you still need help, reset Face ID, then set it up again. Go to Settings > Face ID &Passcode and tap Reset Face ID. Then tap Set up Face ID to set it up again.

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

iPhone Camera

With iPhone 12 models and later using iOS 15.2 and later, you can go to Settings > General > About to see the parts and service history of your iPhone and you can see if the camera has been replaced. If the repair was done using genuine Apple parts and processes, you will see "Genuine Apple Part" next to Camera.

Parts and service history

With iOS 15.2 and later and iPhone XR, iPhone XS models, and later—including iPhone SE (2nd and 3rd generation)—you can go to Settings > General > About for the parts and service history of your iPhone. You can also find out if the battery has been replaced. If the replacement was done using genuine Apple parts and processes, "Genuine Apple Part" will appear next to Battery.

Do you have a disabled Face ID alert on your device?

Please read the "What to do Next" section in this link, if nothing works as per the instruction given in this link --> If an alert says Face ID has been disabled on your iPhone or iPad Pro

Hello,

Apple has several documents helping you with Face ID.

This document is specific to seeing a 'disabled' Face ID alert, and explains what to do when you see that notice. --> If an alert says Face ID has been disabled on your iPhone or iPad Pro - Apple Support

If you don't see a 'disabled' message but do have general issues with Face ID not working properly, explore the list of things to try in this document: If Face ID isn't working on your iPhone or iPad Pro - Apple Support

If the first 8 don't solve the issue then use #9, contact Apple.