Hi

Assuming you followed the Sonos app to add the speakers as surrounds to your Arc (or did you?) what source are you playing to get surround effects. Understand that surround effects are dictated by the source during playback and surround may not be included in some portions of the source material. Please explain what is the source such as AppleTV, Amazon Prime, Netflix or other?

You might try playing a streaming audio source and set the Surrounds to “Full Mode” so they mirror the front channels and see how they sound.

In theory, YouTube TV is steaming, no? If so I can try it there as that's where I the issue so far.  Btw.. Don't have the issue on my other TV.

Thanks for the idea 

Youtube TV is TV as it says in the name as it is coming from your TV.

Stream something from the Internet and you’ll have te full-mode option.

Lots of free options you can add from the Controller if you don’t have something already.

Lol. It's actually streamed from the internet into the TV and my Sonos bar. 

Deal is this... I have multiple tvs that have surround on.  This is the only one with the new 100s. And I've disconnected and reconnected them as surrounds multiple time.  Still doesn't work correctly.

So.. About to junk them and start over with the older ones unless anyone has a good idea 

When ‘TV’ is commonly stated, it means the input coming across either the optical cable, or ARC/eARC across the HDMI cable. ‘Streaming’ means a source coming in via the LAN, either by Ethernet cable or WiFi. 

All 3 tvs are set up exactly the same with the exception of the 100s.  And in the same channel they all act the same.. Except the 100s. 

Not sure why there's any difference. 

Update.  Was steaming music and it did the same thing.  Maybe someone from sonos can help 

Submit a diagnostic and Call Sonos support to have them look at your system internal data.

FYI, for those who are curious.  The answer is :  enable wifi on  the arc.  It was disabled because it was hardwired.  SO we will see if this doesnt cause some other issues.  But there ya have it.  Thanks for all the suggestions

Yeah, that turn off WiFi function is one of the most unclear Sonos “features” there is. 

That bites so many folks, a proper label would avoid much grief.

Instead of “Turn off WiFi” which isn’t what it actually does Sonos could simply say “Turn off the Radio” with a note “This will disable both WiFi and wireless Sub/Surround connections.”

Been asking for years so I’m not expecting it to be under the tree this year.