I've got Sky Q with the Arc but a LG CX and don't have any lip sync issues. My friend also has the same setup and no issues and another has a Samsung and also no issues, all running eARC.  I believe most of the lip sync issues occur with using arc rather than eARC. 

Thnks for reply 

that gives me some confidence in upgrading to sky q 

my previous Sony oled was arc 

new one is eArc 

hopefully all good  

One of the differences between ARC and eARC, as I understand it, is that there’s a “sync voice with video” aspect of the system. Lots of other features, too, but that’s one piece. 

I had just the same problem 

I have Sky Q 2tb linked via TV (ARC) to Sonos ARC.

Tried everything in the settings of TV and Sky but no improvement.

Solution  download latest version of Sky Q software and let the system update.   PROBLEM GONE !

Word of warning… updating the Sky Q box means you will need to relink any Sky mini boxes you have and also relink their remotes to the TVs.

Sonos have great hardware but the software is horrendous. Over the years I think I have spent more time performing software updates and trying to connect to my speakers than actually listening to them.