When the lock screen will have a short gray, and then the screen will be completely black

Rob Phillips

iPhone X & Apple TV Champion, Moderator
May 1, 2012
Welcome to iMore! If you're talking about your screen dimming for a short time before turning off completely, that is how Apple designed it. I like it because it allows me to still see my screen and saves battery by not keeping the display on full brightness when there's a good chance I'm not even using my phone anymore.