LOL. You're right, it's not in there. Must have been somwhere else I read it, was only yesterday.
I had spent a while looking at FAQs on BT, Samsung and Yamaha websites, various forum sites etc. I Googled the model numbers, BT Pro Box and ARC/eARC, before I started posting on here, to see if there was any evidence of other prople having the same issue.
There was, but no solutions, as now confirmed by BT. So I had posted on here to see what feedback I might get.