TV is a Sony XBR-65X900F. A/V receiver is a brand new Pioneer SX-S30. When trying to watch streaming content on an app on my TV, the audio is from my cable box and not from the streaming service. TV is ARC-compatible and I have that HDMI port connected to the ARC port on the receiver. All the HDMI cables are brand new. I've tried setting the receiver to TV mode instead of Cable/Sat and that just mutes the sound completely. Am I missing something? Do I need to run the optical audio cable from the TV to the receiver?