Our RC73 automatically sync'd up with control for on/off and volume after we plugged-in and powered-up our Sony HTNT5 soundbar...
[ per this HDMI ARC connection: at Step 2, under 'Yes' ]; I know it's Sony, but perhaps the same sort of ARC connection may be needed for your connection via TV > soundbar > DTV server (or mini client)? Or, perhaps an alternative HDMI & Optical connection?
Disclaimer: I confess to having no idea what I'm talking about. Nevertheless, just wondering if you have your ARC HDMI > to soundbar > to DirecTV set the same. Have you tried Yamaha (or DirecTV) websites for online Setup/Startup Guides, Support links, or Manuals?
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