I found the "problem". I am such an idiot. Forgot that the optical cable goes from the PC to the TV I use as a monitor.If nothing else try calling Chord support or send them a mail, they are usually quite responsive and can assist on how to proceed and if it is just a setting or something that needs repair...
The other optical cable is plugged into the Mscaler but doesn't go anywhere at the moment (facepalm)