I am unable to adjust my display brightness despite the brightness slider working, so I am technically able to move it up and down but it doesn't translate into a brighter or darker screen. Nothing changed when I tried turning the automatic brightness on/off.
MacBook Air, macOS 14.4
Since the slider itself moves but the display brightness doesn’t change, I’d restart the Mac first. Then try the brightness keys as well as System Settings > Displays.
I’d also install the latest macOS update available for your Mac. Apple notes that software updates can affect display behavior, and macOS 14.4 is an older Sonoma release.
If neither the brightness keys nor the slider changes the built-in display after restarting and updating, that would help narrow this down to a system or display-related issue rather than the automatic brightness setting.
Since the slider itself moves but the display brightness doesn’t change, I’d restart the Mac first. Then try the brightness keys as well as System Settings > Displays.
I’d also install the latest macOS update available for your Mac. Apple notes that software updates can affect display behavior, and macOS 14.4 is an older Sonoma release.
If neither the brightness keys nor the slider changes the built-in display after restarting and updating, that would help narrow this down to a system or display-related issue rather than the automatic brightness setting.
Display brightness not adjusting despite slider movement
