I have noticed that when at about 25-40% brightness you can notice a little screen flicker from the brightness on dark backgrounds. For instant if you use night mode at about 30% there is a noticeable flicker on the screen, not real intense, but still noticeable (changing the brightness higher or page color makes it go away). Is this a defect? Does this happen to anyone else? I wonder if I need a replacement

It seems to happen on any dark background, not on pure white.. any ideas?