Cannot change screen brightness

[Shiroudan]

[SOLVED-GUIDE] 12th gen not sending XF86MonBrightnessUp / Down

this is a linux kernel problem that is kind of tricky to solve. As the way the linux kernel is written devices can be either registered as a hid-sensor or libinput device, but we have a compound device that is both. If you look at dmesg on boot you will see the ec hid endpoint is registered as a libinput device and then taken over by the hid-sensor-hub driver. I have a thread with some of the linux hid subsystem maintainers, and the conclusion is the way the Linux Kernel is currently written, …

It sounds like it’s most likely this problem!

First try seeing if disabling fn-lock (by pressing Fn+Esc) works though!
Updating the BIOS most likely makes this not persist.