Flickering screen problem when brightness is below 100% (Dell XPS 12)

Hello.

I have a strange problem: my screen is flickering/flashing really bad. However, this disappears when I put brightness level in 100%.

I've always used brightness levels between 40 and 50%. Today, when I turned my PC on, the screen was flashing really bad. I tried a lot of things, and noticed, by accident, that the flickering stops when I adjust brightness to 100%. Unfortunately, I can't use it for a long time in 100%, because it hurt my eyes.

I just want to know: how can I fix it, to be able to use it again in 40-50% brightness, without this annoying and eye-hurting flickering effect?

I attached a video showing the situation. Although the cell camera may distort something, when it films a screen, it is possible to notice that the screen flicks really bad, and it just stops when I adjust brightness to 100%.

As this video has 2,91Mb and Dell just accepts files with maximum 1Mb, I uploaded it in Dropbox, and I am sharing its link. I hope this works: www.dropbox.com/.../Dell

Please, help!!!