screen brightness not working after update (solved)
backlight slider stopped working on my amd ryzen 2500u laptop, KDE was using a fallback option with dimming the image(this was bad) without any error messages(not even in dmesg or when using light command that affected nothing)
I had to remove acpi_backlight entries with grubby to make it work again
you check like this: sudo grubby --info=ALL | grep args
then if you see acpi_backlight(for instance acpi_backlight=native, or =vendor) you can run
sudo grubby --update-kernel=ALL --remove-args="acpi_backlight=native"
(replace ALL with the one you want to change if you don't want to change every kernel args)
more info here https://hansdegoede.livejournal.com/26427.html
it happened to me on fedora 41 recently so I guess it makes sense to post this to make it easier for others to google the solution