Touch Bar Macbook Pro disappeared, still not back after complete formatting

Hi,

I own a Macbook Pro 2019 i5.

A few months ago, my Touch Bar started regularly "disappearing" then coming back. Recently it completely disappeared (except for very few occasions where some buttons are showing). I tried all the terminal things, and even completely formatted my hard disk and reinstalled Mac OS. It's still not showing anything.

Any advice please? Thanks!