Laptop screen becomes too dark when unplugged

My issue is that when I plug in my laptop to charge, the brightness increases from whatever level it is on. when I’m in a bright environment and unplug the device though, this brightness drops too much, and the screen becomes dark even on the highest brightness setting.

A related issue is that if I’m working in the dark and plug in my machine, even if I have the laptop on lowest brightness, the brightness boost bumps it up a lot (this isn’t like an increase on the brightness meter that I can turn down, to be clear) and makes it painful on the eyes to use.

Is there any way to avoid all this?

Have a look at your power settings in Plasma:

This is where you can configure the brightness you want when unplugged (or disable it). Make sure to choose the correct tab above (“On Battery”, “On AC Power”, …).

in all three modes change screen brightness has been turned off. however, plugging in the device still boosts the brightness somehow.

Does your laptop’s BIOS maybe interfere?

if so I wouldn’t know how to diagnose it, I’ve been scared to open into the bios menu ever since I tried to dual boot this machine, lost my windows installation and have been in arch since.