Hi @jayh89, Thank you for reaching out and getting our attention to this.

We don’t know why the passthrough option was removed. In this case, we recommend calling the manufacturer for more information.

Only they’ll know why the passthrough option disappears.

What Sonos speaker is connected to your Samsung TV? and what connection it’s using? (HDMI or Optical)

Are you also having TV audio issues with the Sonos speaker? If so, take a diagnostic from the Sonos app; so we can check the system.

Setting > Help & Tips > Submit Diagnostic and post your confirmation here.

If you have other concerns, feel free to reach out.

Hey. It’s Sonos arc and I’ve ran a diagnostic using a Dolby atmos movie. Can you see if atmos is working ok? 1572388235. 
 

and this is on a 5.1 movie - 1183208865 (the app says “Dolby multi channel pcm 5.1” but it used to just say Dolby digital 5.1. What’s the difference??

Hi @jayh89, thank you for the update and for taking the time to troubleshoot this.

I checked 1572388235, Sonos Arc is receiving Dolby Atmos while the Sonos Arc is receiving Dolby digital 5.1 in diagnostic1183208865.

So the Sonos Arc is communicating well with your TV.  

The difference between Dolby Digital and PCM is that PCM is lossless and Dolby Digital is compressed.

Also, PCM is stereo sounds emulating a surround sound feel while Dolby Digital emulating a Cinema-like feel in your own home.

The 5.1 is simply the Left, right, center, rear right, rear left channels for the “5” and sub for the “.1”.

The Movie you were watching is probably encoded in Dolby multi-channel PCM 5.1. It depends on the Audio encoding form the source on what the Arc is receiving.  

If you have other concerns, feel free to reach out.