Thanks for the replies, sorry I'm late getting back.
I use optical out via TV, to an optical switcher connected to my speaker decoder. It's been like this for years. Obviously it's a good call, cos it's not a usual setup and has many parts. But my TV's Netflix app never gives me issue, just the TiVo. This issue has happened on an off over the years for a long time.
I'll turn thing on andquantitative easing, off, have a fiddle with cables and get back if I have anything exciting or useful to tell.