My Face ID stopped working on iPhone x

If you already tried (to no avail) ALL the steps provided in this support article:--> If Face ID isn't working on your iPhone or iPad Pro – Apple Support, contact Apple Support directly, using this link:--> Get 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