The device was faulty though.
Source: https://youtu.be/vj8DzA9y8ls
spoiler
It's almost certainly due to faulty hardware
the biggest problem is my second 1080p monitor I Super Resolution to fit more programs on it.
Gotcha, DLSS/Super Resolution just don't seem to fit the OP's question at all though. The monitor scaling I replied with would allow to fit more windows on the monitor (though they will appear smaller as they'll have less real screen space while having their old virtual screen space). I don't understand at all how DLSS/Super Resolution would be related to that.
I don't fully understand how upscaling low resolution would give better readability for many small windows on the same screen? I know Nvidia's DLSS but isn't that made for running games at a small resolution and stretching/upscaling that to fit a far bigger monitor?
https://github.com/arindas/manjarno has a list of their prior adventures. EndeavorOS is the closest alternative AFAIK. But for now I guess that they are fine there. Just a heads up for OP to know to expect that something might be coming again and if they ever have a chance to choose another OS due to a fresh install that Manjaro isn't the most recommended distro out there.
I don't know what "super resolution" actually means but if you're on Xorg / X11 then you can set arbitrary scales for your monitors if you want a 1080p monitor to have 2 times as many virtual pixels than its native resolution then you can run xrandr --fb $((1920*2))x$((1080*2)) --output --pos 0x0 --mode 1920x1080 --scale 2x2 fb is the whole desktop size, increase it if you have multiple monitors. For finding out what ID you need to give for --output run xrandr without any arguments and try to recognize your monitors, or trial and error. Pos is position, if you have several monitors then your 2nd monitor should not be at 0x0 but somewhere like 1920x0 for example. Mode is the unscaled resolution you want to give the monitor, with scale 2x2 an actual 1920x1080 will be 3840x2160 virtually, your fb parameter needs to be configured WITH the SCALED size, not unscaled.
For Radeon Software I found https://www.amd.com/en/support/kb/faq/amdgpu-installation on AMD's site but I would heavily recommend that you first try to find if your distro has already repackaged it somewhere.
HDR seems to be experimental/in development for Linux for now. If you decide to tip your toes in there expect that you may find some rough edges. https://wiki.archlinux.org/title/HDR_monitor_support