In the Sonos app, go to App Preferences and disable Hardware Volume Control. Then adjust the volume on the TV and turn it off. Turn it back on and see if the volume is the same.

You can also try disabling and re-enabling TV Autoplay under the Amp settings.

I will try it and let you know 

Unfortunately, this didn’t work. I turned the tv on the following day and volume was at zero. I checked the settings and they were still as I set them, yet the volume setting did not hold.
 

When I turned the tv off, volume setting was at number 18. When I turned it back on it was at zero. Any other feedback is welcome. @Sonos, is this default to zero by design or should the volume hold last position? 

Hi @MLove 

Welcome to the Sonos Community!

I too have a Sonos Amp connected to my TV, and what you describe does not happen to me -  nor should it - so I can only presume that your TV is sending a signal, via CEC, telling your Amp to set it’s volume to 0. One way to confirm this would be to connect the Amp to a different TV and compare results.

Does this happen every single time you turn the TV off and on again? Or, does it only happen during the night when the TV has been off for a while? It’s possible that the command to turn down the volume is in fact coming from a different source, during the night, but if the problem occurs every time you turn the TV off and on again, then it is most likely the TV.

The sources of volume changes are recorded in the speaker’s logs, so you can find out for sure what the source of the volume command is by getting in touch with our technical support team, who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports.

I hope this helps.

I did notice, when I turn the TV (Sony X90j) off and back on with-in a few minutes, it holds the volume setting; however, if it’s over night, the volume is back to zero. 

My only thought is, what other sources could it be??? I guess working with tech is my option???