I have the same issue but in my case it's with my speaker set, which is connected to my PC with a Optic cable.
When I use my headset which is connected to a USB 3.0 Slot it does work (after a restart of the game application).
Also I ran the EU4PrereqSetup_x64.exe but the only thing I could do with that is 'uninstall'. I assume it means uninstall the game.
I will do the one option it provides me. At the worst I just have to reinstall the game through Steam.