The lip sink is out on my new(est) Samsung telly (32H5000), it's bad (even on BBC) when the HDR is set to 0ms and gets worse when increased. Lip sync was fine on the 32EH5000 - I had it set to 80ms IIRC.
John Lewis have a significant number of reviewers who have lip-sync issues with the 32H6400 but no complaints about the 32H5000.
I've heard the 32H6400 lip-sync for myself. It was grossly inadequate even when using its own freeview tuner and speakers. The Samsung's menu lip-sync setting could not go far enough to totally compensate. The amount of adjustment needed also varied within the same programme - occasionally it was almost OK.
I can't remember where I have seen it but I have read a review which claimed that Samsung support claimed that Humax PVRs caused lip-sync issues.
On the 32H6400 the lip sync option was called 'Audio Delay'. In both the 32H5000's and the 32H6400's User Manuals it only mentions the adjustment function for the digital audio output of the TV, but the 32H6400 could be adjusted for the digital inputs as well. I presume that the 32H5000 is the same.
I eventually tracked down the delay setting on the audio output sub-menu, and ramped it all the way to 250ms, but it doesn't seem to make any difference to the TV screen/speakers. Different settings are stored for the various input sources as well.
The snooker makes a good reference with the clinking of the balls, and there doesn't seem to be any problem today. Maybe it's particular channels and even particular programmes. Any small amount of delay from picture to sound is acceptable, because that's normal in nature. Sound preceding picture can't be tolerated, which is why there are settings to delay the sound to compensate for video processing delays rather than the other way around.
I have pinned the blame for this on my HDMI 4x2 matrix switch. If I switch sources on the TV and then back again so that the HDMI resyncs, the sound syncs up. Not conclusive I know, but as it's unlikely to be the TV or the HDR, that leaves the matrix.