it definitely has played through the USB because it sounds crisper and louder. Also, when it's playing via USB in the Output settings it doesn't show that it is playing via Bluetooth, but when it is playing via Bluetooth it shows that is the option selected. I've tried everything to try and get it to route via USB, but can't find a replicable way to do it. I just end up disconnecting the Bluetooth until it finally stays on USB output.