I'm dual booting Pop_OS and Windows 11 for now while l try things out. I went with Pop_OS for the NVIDIA drivers, since I have a NVIDIA card. Installation went smoothly, but setup is where things started to get a little weird.
I have 2 monitors, a main 360hz monitor and a secondary 165hz monitor. I seem to be able to have them both working at the same time in Windows 11 without issue, but in Pop_OS, setting the refresh rate to 360hz on the first monitor causes both displays to stop working properly. The 360hz monitor will stop displaying picture all-together, and the 165hz monitor will start flickering wildly. Turning off the second monitor brings the 360hz's image back, but then I'm down a monitor. Also, if I set the refresh rate to anything lower than 360hz, they'll both work. I'd like to still be able to use it at the native refresh rate, but I can't seem to find any other solutions or anyone else who seems to have had this same issue.
My second (slightly less annoying) issue is that I can't seem to use HDR in games. Is this normal, or is there something I can do to bring back support?
Also, if Pop_OS isn't the way to go, please let me know! I tried Nobara first, but immediately had issues with the displays locking up and flickering before I even got it installed.
You are likely using X11. X11 treats all enabled displays as one "screen" and therefore different refresh rates will have issues (as will VRR for example).
Wayland is the way to go, but the NVIDIA drivers are still buggy with Wayland. Pop!_OS currently uses a desktop environment based on an outdated version of GNOME, so it probably won't be amazing under Wayland.
I'd recommend using a distro with a recent version of KDE Plasma as it has non-experimental support for VRR and great support for Wayland. You'll also want an up-to-date kernel and the latest NVIDIA drivers. I recommend Fedora KDE Spin or openSUSE Tumbleweed. Installing NVIDIA drivers is a little bit more involved (search for "RPM Fusion NVIDIA" for Fedora), but very doable.
I personally switched to an AMD GPU because of the issues with NVIDIA, but NVIDIA support is improving so you'll probably be fine.