Is there a chance that your TV’s speakers are still turned on? That might cause at least some of the issues you’re suggesting. 

I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, there are more options available beyond just the diagnostic analysis.

Thank you. I have an older TV that has only optical out for speaker bar. That didn’t work when I plugged beam in. So, I went direct from my COX cable box optical to gain channel sound. Issues I’m experiencing are the echo, and I’m unable to mute or shut off the Beam. Thus, I turn sound down when turning TV off. I will check to see about sound settings. You maybe correct. This began after I did the TruPlay with my iPhone. 

I think TruePlay is a red herring here, but of course I’m not in front of the TV. As suggested, running the diagnostic and either calling in, or posting the number here would certainly help determine if the issue is internal to the Sonos system. 

That fixed it. It was the Smart Aquos TV repeating to echo. But now my Beam is at max volume via on screen popup, but not loud. How do I get it louder? I did the app and it shows Max as well. 

How do I run diagnostics. I found how to do on Google. I’m no pro as you have guessed. Thank you. You helped me figure this out. I found the sound was lower by Sonos app at 34%. All is working great now. Next comes the one back speakers. Thank you for your patience and knowledge. 

If you click on the words “system diagnostic” in my original answer, it will open up the FAQ that tells you how to submit a diagnostic.

Odd that it was set to 34%...that’s something that is set on your end, and not an “automatic” change by any stretch.

Glad you’ve got things heading in the right direction. Enjoy your Sonos!

Thank you, again. I appreciate your skills.