Dell P2317H moving gradients problem

Hello, i bought Dell P2317H, and like this monitor very much. But there is a problem that i noticed, while using it. When there is a change of tone on a monitor (in video games and movies when a picture changes from light to dark, a rising sun for example, or change of tone in a sky, or in windows welcoming screen when its changing) there are noticeable lines of gradients present. After testing more i noticed that when changing from light (or dark) tone to another one, it gets these lines. An example of this i managed to replicate is scrolling up and down this gradient picture (in browser or program)

i get horizontal lines on it. I do not see any gradients or lines when picture is steady and when i move it slow, but zooming in, and scrolling up and down produces said lines. I have another monitor, a notebook, and scrolling this picture i get no lines.  This issue, like i said, is also present when gradients changing in games and movies. It is very disappointing, and distracting. 

I tried hard reset, tried different cables (HDMI, DP), and tried connecting monitor to my notebook. Issue still remains. I also tested that only setting that is influencing visibility of those lines is "contrast". Only on 40 to 45 contrast there are no noticeable lines.   

Please tell me, is my monitor broken? Is there any way i can fix it? I like it very much, and would love to keep it, but this problem with gradients is bugging me out. Thank you in advance.