Comment 22 for bug 1720438

Switching to integrated graphics the Fn works perfectly on gnome. Also:

ls -l /sys/class/backlight/
total 0
lrwxrwxrwx 1 root root 0 may 5 12:12 intel_backlight -> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-eDP-1/intel_backlight