Line on screen

Hello, brand new iPhone 13 Pro Max have a problem (I hope that it is just software bug). The problem is that when i connect it to charger or to Mac, after I lock it (turn of the screen) some kind of horizontal line appears on the screen and 1/3 of the screen is brighter then the rest of it. The line dissappers when I restart iPhone. I tried turning of TrueTone, auto brightness and tap to wake, but without effect. I have also noticed that when I connect it to charger and keep the screen on, the line won't appear. As soon as I lock it and the line appears.