I like to play games on a CRT monitor on 1024x768 @85hz which wasnt a problem on windows. I recently switched to Fedora 40 because I wanted to get back into linux. I have an AMD card and most answers to this question have been for nvdia cards. After I go through all the steps of changing to kde x11 and making a profile in xrandr everything seems to go smoothly (No errors, etc.) So upon going to my system settings to look for my new resolution and refresh rate just to not find it in the list of resolutions. Why cant I change to my new resolution? What am I doing wrong?
We will need more information to be able to help you.
What I am wondering is if your monitor claims to support 85Hz.
What is the output of inxi -Fzxx?
What is the output of xrandr --verbose?
What is the output of kscreen-doctor --outputs?
You might need your monitors EDID to analyse it, but I’m not near a none VM Fedora to check the command to use.