NVIDIA backlight not saving brightness value on shutdown correctly

I am using the Manjaro KDE image with proprietary drivers.

My laptop does not have an iGPU, and I figured out that acpi_backlight needed to be set to “none” (makes sense since brightness won’t work on Windows until the NVIDIA driver is installed)

So now systemd-backlight@backlight:nvidia_0 works correctly on bootup.
But, on shutdown the backlight value does not save because if I manually do
sudo /usr/lib/systemd/systemd-backlight save backlight:nvidia_0
and the brightness was 35% then next boot would be 35% brightness.
However, if I change the brightness to 50% and reboot the brightness would still be 35%.

Do I need to mess with the service file so it does its thing earlier? Is there a less janky way to fix it?

I got a similar issue, the only 2 difference is:

  1. I’m using KDE on arch, but not Manjaro
  2. I didn’t set acpi_backlight to be “none”
    But the result is the same as you: “on shutdown the backlight value does not save”
    and sudo /usr/lib/systemd/systemd-backlight save backlight:nvidia_0 can mannually save certain brightness.
    Did you figure out a solution?