The keyboard volume controls have no effect on my 2018 MacBook Pro. The context menu of the volume dropdown shows Cmd + and Cmd - should control the volume but they do nothing in either System volume or Internal vol.
The only volume control I have is using the mouse on the slider. The Mac's volume buttons on the Touch Bar also do not work as already reported here:
https://yabb.jriver.com/interact/index.php/topic,115497.0.html MC 24.0.45