No "Adjust keyboard brightness" after updating to macOS Big Sur

Hi Panha_Hok,

Welcome to the Apple Support Communities and thanks for posting about your Mac issue here! We'd be glad to help take a look into this with you. First, we'd like to ask you a few questions to ensure we're on the same page. Are you referring to the "Adjust keyboard brightness in low light" option in System Preferences > Keyboard? Or are you only missing the Control Strip on your Touch Bar that allows you to adjust your brightness manually?

To learn more about how to adjust your keyboard's backlight or Touch Bar, check out these support articles below:

Turn your Mac keyboard’s backlighting on or off

Customize the Touch Bar on Mac

Let us know if these help. Cheers!

I'm having the same issue.

1. The keyboard backlights turns on only at login screen. Once I enter my password they turn off
2. The option in the Touch Bar does nothing anymore
3. the option/controls on the screen do nothing
4. The option to "Adjust keyboard brightness in low light" dissapeared from System preferences