If you are watching a 5.1 audio source, the dialog should only be coming from the center channel speakers of the Arc, not the rear surround speakers.

The “full” setting for the rear surround speakers only affects the audio for music playback. It doesn’t change the surround audio when in TV mode. What plays out of your rear surround speakers in TV mode is dependent on the audio source.

I hear you but I had it coming from the ARC “center” and also the rears.  Now that it has stopped and I only get what seems like ambient noise from the rears its not nearly as impressive.  

That’s how discrete multichannel audio works. The audio channels are separated for a more realistic audio experience. If someone on screen is talking, you don’t want to hear their voice behind you. Similarly, if a car explodes behind you, you don’t want to hear it explode in front of you.

5.1 audio is what you want to have playing out of your 5.1 home theater setup. When you hear dialog from your rear speakers, you are probably only watching a Stereo 2.0 source.

FYI… if you don’t like discrete multichannel audio formats like Dolby Digital 5.1 or Dolby Atmos, you can always set your TV or media device to output stereo audio only, but this would defeat the purpose of having a 5.1 home theater system.

I do appreciate the feedback and it makes sense what your saying.  I just got a new smart TV and that’s when it started.  Probably working the way it should be now because the Sonos app is showing Dolby digital plus 5.1 and on my previous tv it didn’t show that on the app. I think I just got used to the noise around me the entire time with them talking. 
 

thank you again.