Go to the TV Dialog sync setting. Experiment a little. You'll get it.

Set the Digital Output Audio Format setting on the TV to Pass-Through, not Auto.

Voice is ahead of lips. Spent lots of time on phone w Sonos and the app is maxed at 5. Needs to go to 6 or 7 to synch but the app does not. Very dissatisfied 

That’s really odd. I wonder what is adding the extra processing time to the video, and not the audio? Seems weird to be delivering the audio more quickly than delivering the video. Sonos plays it pretty much as quickly as it receives the data, as you’ve found out, there’s not a lot of options for delay. Most people have issues in the other direction, where the voice is trailing the video. 

I'm having the same issue with the Beam 2 and the same TV. Audio is ahead but the Sonos setting described above doesn't fix the problem. I'm not willing to disable earc and Atmos because that is why I bought this setup. Getting worried that people aren't finding solutions to this problem.

What I find interesting is the delay builds over time an gets worse and worse, until you pause and restart. No additional delay on either end can fix this, because it is not a fixed delay time.

Frustrating when I have what I would consider a high end setup. My 5 year old LG doesn't have any of these problems.