I had this issue but I updated the Sonos system software today and the issue was fixed. 

Hoi Barack,

Welke update heb je nu dit is opgelost?

Groetjes 

Claudio

Thanks for reporting.  I updated my Sonos system the other night after reading your thread and have had minimal issues yet.  I am still holding out for more time to see if it is resolved but I am hopeful.  Thanks!

I had this issue and had been trawling the internet for a solution and couldn’t find anything. 
 

Anyway, it could have been totally coincidental but I had the Sonos app open on the ‘TV’ page (with the volume, night mode, speech enhancement, etc), I then changed the volume on my remote with the screen on my phone open, and I could see the volume indicator moving on my phone. 
 

From this point on, the remote was able to change the volume as per normal and without the Sonos app open. 

I have been waiting to see if the issue was totally resolved but it still is happening.  It isn’t nearly as bad as before but you can clearly see with the Sonos app open on my phone that not every volume button press on the remote registers with the speakers.  Come on Logitech or Sonos.  You can do better than this!

I don’t know who’s to blame here. I use my Harmony Elite remote in my bedroom, with no issues whatsoever. My source is an Apple TV, the TV set is a Vizio.