MacBook Pro dims display to 50% when charging cable is removed

When I remove the charging cable, the brightness of the screen is reduced to 50% from 100%. If I plug the cable back in, then it goes up to about 75%. It then drops again to 50% when I remove the cable. I would like to prevent the screen brightness from changing unless I change it manually with the screen brightness keys. What am I missing? I have the following configuration: - System Preferences > Battery > "Slightly dim the display while on battery power" is **off**. - System Preferences > Battery > "Turn display off after" is set to **never**. - System Preferences > Displays > "Automatically adjust brightness" is **off**. macOS Monterey 12.3 (21E230).