Oops! "Sent from Outlook for IOS" explains your confusion - Apple!. Device Manager (DM) is a Windows tool that provides you with a list of all the hardware that the operating system (o/s) has recognized that are connected to your PC, and has installed hardware drivers for. I haven't the faintest what is Apple's equivalent tool - perhaps your favourite Apple support group can help you here, or a simple search of the Web for Apple's equivalent. Anyhow, DM will report under communication devices/USB devices the presence an ATEN unit (or whatever your converter is), and you are able to see what driver has been loaded to interact with it, among other things.
If you can get that far, it would help in the troubleshoot.
Paul.
