I have a Pioneer Vsx-d710s surround sound system. When I plug into my PlayStation 4 via optical it works but only on FL and FR speakers, the surround sound speakers have no sound. I went into test mode and it transmits sound to all speakers so I don't know how to make it surround sound. I've downloaded the manual and tried to navaget to the correct setup but I'm struggling. This was working in the past so I know it works but I've moved house and haven't powered on for over a year until today. Please and thank you