Flickering backlight on alienware 15

[d3day]

From the beginning it was interesting to install gentoo on my brand new alienware 15 for all but gaming. Basically kde-systemd way was chosen.

I've installed the kdebase-meta and was happy that backlight using Fn and f8-f9 key worked perfectly except the weird % levels it showed (49%-59%) when used. Also on low levels of backlight I noticed horizontal stripes as of the refresh rate was way lower than 60Hz. I tested it with the phone camera and confirmed it. Not sure how to fix this issue and what could be the cause. Also it's not reproducing on windows. On higher levels of brightness camera was not able to show me the stripes however the screen was not comfortable for eyes and I've got that weird feeling like I'm looking into CRT in win 95 times. (xrandr showed 60Hz rate on 1920x1080)

Another problem is that on dark background (like terminal) the backlight is rapidly changing from lighter to darker and it driving me nuts very quickly. Afaik it could be something like an adaptive brightness in windows but not sure how to configure it.

Can anyone suggest any ideas where to look to identify the causes of these problems and possible fixes?

P.S. I'm kind of new to linux desktop but had a bit of background with servers on debian an centos.
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