Why my face id on iphone not working

If you receive an alert that FaceID is disabled on your iPhone or iPad Pro

It can occur that you will receive the following message on your iPhone or iPad Pro : " A problem was detected with the true depth camera, FaceID is disabled"

When you're getting this error message, Make sure that you're iPhone or iPad Pro is running the latest version of iOS or iPadOS. If your device is running the latest iOS or iPadOS and you're still getting this message and FaceID is not working:  contact Apple Support to get your device serviced.

If the issue persists (after performing the steps provided in the support article that led you here), contact Apple Support directly, using this specific link:--> Apple Support , or make an appointment and have your device inspected at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> Apple – Location Selector. After checking it out, they'll give you all the available options.

Regards

Giulio