iPhone 8 plus shows horizontal dotted lines when turns on

Hello everyone,

I am using an iPhone 8 plus with iOS 11.2.6 and recently I found that when I turn my phone on, when the screen with the Apple logo comes, some horizontal white dotted lines are shown in the black background. These cannot be seen if I am in a bright environment. The lines are so thin and disappear quickly. The position that the lines lay is random. So I guess the problem is not with the display. One of my friends said that he has this issue with his iPhone 8 plus and that's when I checked my phone and found out that I am also having the same issue.

Is this something normal that everybody experiences, or is it a software or any other hardware issue?

Please help me to sort this out because this is my fist iPhone and i don't have much experience with iOS.