system details - AMD Ryzen 5 5600H + nvidia 3050Ti
so i bought this system 6 months back , tried dual booting immediatly.
tried few debian and arch distros, same inverted brightness problem. so i removed dual boot and used windows and WSL2 for 6 months.
i again tried dual booting linux with endeavor today, issue is still there (i think it’s bug with victus or amd-gpu) . So after searching diff forums, found this
step 1 - set kernel parameter to acpi_backlight=vendor.
step 2 - and use this tool (which use xrandr to adjust brightness) - https://github.com/LordAmit/Brightness
now i’m able to change brightness