ok, they have messed up a windows update, and its disabled the sound... i thought that USB and monitors devices as you said are separate audio devices.. so it might not bw wortth the quick fix im thinking, Ive tried a USB Jabra and Lenovo speakers on a monitor via USB C, and still nothing ,
most usb devices arent locked down, unless specific admin rights are needed for an installer package.
ie for printers, you can install with the inf files but not if it a setup.exe with bloatware.
I think i have a USB soundcard at home in a drawers somwhere i will give it a try.