This is common when USB-connected audio devices have their own volume controls. The OS sets the volume to line-level and lets the USB device deal with it. Check to see whether your Bose has its own volume controls.
all I got is this-a product reset. Turn off the device , unplug the power cord from the outlet, wait about a minute, plug 'er back in. otherwise, mess around with AudioMIDI or check for any system updates
sorry-bose ain't a whole lotta help, and neither am I , today