Some users report that the keyboard audio volume controls fail to work properly under Mac OS X 10.4.4 One reader writes "Since updating, the F3, F4, and F5 keys no longer work for controlling volume.
I have a monitor which is connected by display port, and speakers connected to the monitor via old-school 3.5mm jack. macOS (12.2.1) recognizes that sound output, and I can hear my system sounds ...