The front camera on my IPhone X is not working. The 2x function is fine and the rear camera is fine. What should be done?

I believe it is a hardware issue and the phone has to be serviced by Apple or an Apple authorized service provider.

Review the below 2 articles for more information.

If the camera or flash on your iPhone, iPad, or iPod touch isn't working - Apple Support

Get your iPhone, iPad, or iPod touch ready for service - Apple Support

Do you see anything strange, weird things happen when you shake or do something to the camera (When you look at the lens)

Apple has decided that you are in need of a new device. Please bring a form of payment and submit your old phone to an apple store to receive a new device, at full cost.