A:AnswerI assume you are changing the settings in Windows for the display. If you are not showing that available it is probably your system or game that are limiting it.
A:AnswerYou have to use the display port cord to reach the maximum potential. Go into settings then display settings and change it to 165. I had to do it as well and thought something was wrong but nope just wrong cord.
A:AnswerDepends on what you’re playing it on. Series X isn’t going to exceed capabilities here. Easily able to get the monitor set up for your subjective preferences. Try it out. Decide what works for you.