Hi All,

 I have the LG CX and just got my Sonos Arc + Sub. I have the arc hooked into HDMI 2 for ARC/eARC capabilities and when using apps through the TV itself, the audio is output in Dolby Atmos (when possible). However, when I try to use my FireStick4k (LG doesn’t have HBO Max app yet) plugged into HDMI 1, all apps show the best possible audio output as 5.1.

 I have my TV set to output via HDMI ARC, I have eARC turned on and I have the output set as Pass Through (although I changed it to that setting from ‘auto’ after already using and setting up the Sonos Arc). I also have updated the settings in my FireStick4k to Dolby Digital+ for audio.

 Is there anything else I can do to get the Atmos sound to play through the Arc when using my FireStick? Is it possible that I need to reset my TV and redo the audio and set it to Pass Through before playing any sound through the Sonos Arc in order for other HDMI ports to receive Dolby Atmos audio?

Thanks in advance!