Touchbar is dark on Macbookpro 2018

Hi,

For 2 weeks now, my touchbar is darker on my macbook pro for no reason. It looks like luminosity is set to low and shortcuts still work as normal. Sometimes when I restart computer it's coming back and then it's leaving again. It's driving me crazy.

I contacted apple support by phone which gave nothing except "try to take it to an apple store, we can't find a slot for you".

I'm pretty sure the bug is software origin and not hardware. Has someone experienced the same thing ? Is there a thing to do ? command line or other ?

For info : MBP 15" bought sept 18.

Thanks,

F