I've purchased a Dell XPS 15 9520 with the OLED screen, that is said to be great in all reviews. However, I find it to have a very annoying defect. It seem to have a consistent "dot" pattern to all the screen, especially noticeable on white/gray backgrounds.

Not that it's the end of the world, since I can use the laptop anyway, and in dark screens it looks good, but I'm very disappointed after spending a lot of money to find a defect like that.

Has anyone the same problem? Is that a defect of the screen, that can be replaced in warranty, or it's a common problem with OLED units?