Audio problems with the optical connection are normally caused by a faulty cable, poor connection, or improper sound settings. ➜ Confirm the input function of the sound bar is set to optical. This feature is available on certain digital broadcasts and streaming videos and isn't supported on standard cable or analog stations. If the video doesn't contain. HDMI-CEC handles that for HDMI cables, but for optical, you must pick up the soundbar remote and press “Input” or “Source” until you see “OPT,” “DIGITAL,” or “D-IN” on the display. Original content by hifireport. I use Plex, regular cable TV, Apple TV 4K+, and a new Dune media player. I never had this issue when I was doing hdmi pass through on that same receiver from OpenPHT on the home theater pc I was previously using.