Excellent news that you've now been able to replicate the FF sound loss problem so hopefully a fix will not be too far off.
Re your last message that you are continuing to investigate the other audio related issues in parallel on the assumption there will be different root causes, could you please confirm that these issues include the "Skip button" problem that I and others have mentioned, whereby instead of the recorded programme going forward 60 seconds it actually goes backwards to a random earlier point.
Can I also ask a question that I am sure must be related to the FF sound loss problem which puzzles me as a novice in these matters. It is my understanding that all recorded programmes, whether Freeview or Subscription Channels recorded from the internet, are stored on the hard drive on the YouView box. However, whereas Freeview recorded programmes do not require the YouView box to be connected to the internet to watch them, those recorded from the internet do require the internet connection to be in place before they can be watched. Why is that and what information has to be accessed from the internet before such recordings can be watched. Is the way that the two sets of recordings are stored on the hard drive fundamentally different?. Which of these “differences” is causing the loss of sound problems with internet recordings but not Freeview recordings.?. Grateful if you or one of the other "recognised experts" could enlighten me.
Its obviously very good news that this problem (FF sound loss) has been replicated by BT, but considering this thread started in September 2017 and there are others that predate it by several months, its baffling to me that it has taken BT at least 18 months to replicate a fundamental issue which occurs with 100% regularity for customers... it really takes no special effort at all! I therefore suspect this is the first time an attempt has actually been made, which on one hand confirms my suspicion that until now the issue has been broadly brushed aside, but on the other, more positively, surely it will be solved now that it is actually being dealt with. All I need to know now when the solution is found is if this is to be solved by a downloadable software update or a new box. Please keep us posted, thanks.
another way to get it back is to goto settings, change the display to a different resolution, then change it back again and save.
Interesting, will have to give that a go. But it does suggest that it something to do with HDMI synching although why that would affect optical audio out and analogue audio out too is curious. I thought I had been reforcing an HDMI synch by changing input on my TV away from and back to the Youview box but perhaps not?