Did you try this solution mentioned here?
"Adding just acpi_backlight=native worked for me.
grub line becomes:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=native"
Ubuntu 24.04
Acer Nitro 5 AN515-47
Following steps from Pratham:
- sudo nano /etc/default/grub
- Replace GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" With GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=native"
- press ctrl+o, then enter to confirm, then ctrl+x to quit nano
- sudo update-grub
- reboot your system
"
(I changed gedit to nano and adapted it so that you can use the commands on Zorin)
That's the part of the original file which you need to edit (it may look a bit different on your system, I use the Zorin live boot stick at the moment)
Only change the one line there which begins with GRUB_CMDLINE_LINUX_DEFAULT, so that it looks so:
