It is beyond me that you would buy an expensive speaker and not want to use it………

Though you are certainly not the first one to complain about it.

It is not about the expense of the thing, more of it all working properly.

According to the HDMI-standards everything is working properly: when the Arc is connected it is always used for sound. Or do you have another problem?

There is an option on the tv to use audio system (sound bar) or tv speakers, i have my HiFi connected to the tv via optical cable and to use this you have to go through the tv speakers, but when i select tv speakers it just flicks back to audio system.

Not that it is how you want it, but according to the HDMI-standards this is how it is supposed to work: using a soundbar with HDMI-ARC/CEC channels all sound to the soundbar. Other possibilities are closed.

I know what you are saying, but it worked with an older sound bar, and it worked with a different model sony tv and sonos arc in the Richer Sounds shop.