Scarily this thread from 2016 seems exactly the same as the issue I have: https://community.sony.co.uk/t5/other-tvs/lip-sync/td-p/2252004

Watching Freeview (OK, YouView) channels and listening on the internal speakers there's a slight, but disconcerting, lip sync error, coupled with the feeling that the voices aren't coming from the mouth of the person speaking.

The TV is on a stand in a corner, so I selected "stand" for its location.  However this seems to throw the sound into the corner, making it very muddled.  Switching to "wall" is loads better but of course only slight errors are quite maddening!

Based on the thread from 3yrs ago, I'm wondering if this is just how Sony TVs are.  Is there anything I can try, before it goes back?   I will say we had a cheapy Toshiba (Vestel) TV for the last few months and the one thing that did really well was sound!