Problem with Face ID - Iphone X

Good evening ,

I have an Iphone X

Suddenly he did not recognize my Face ID and so I started to Reset and Setup the 
FACE ID again from the beginning.

After the Reset I did , when I went to do the Setup again I get back
 problem "FACE ID is not available"

-I did a Force Reset with Volume Up + Down as we all know.

-Front Camera works normally

-The Sensor for the brightness of the screen and to turn off the screen when 
I put the mobile phone in the ear at the time of the call works normally.

-The software is on the latest IOS.

- I reset the settings.

After all this, it still does not work and I can not setup it.

Can anyone say any ideas?

What could be wrong?