Another update. My dropouts started to get more frequent again.
So I called into Richer Sounds, who sold me the TV, and the guy there said he had lost count of the number of customers who had had similar HDMI problems with this LG TV. His considered advice was "go back to optical and stick with it"!
So I decided that the time had come to abandon the LG's sound processing and just use the TV for the picture! I purchased a Denon AVR 1400H and some small speakers and then routed the Humaxes etc to it. The HDMI out of the Denon goes to HDMI 2 in on the TV with ARC enabled. Everything works, no audio or video problems, I even get Atomos 7.1 out of the TV. A happy ending for me, but admitting defeat in that LG will never fix their sound processing bugs.
So I called into Richer Sounds, who sold me the TV, and the guy there said he had lost count of the number of customers who had had similar HDMI problems with this LG TV. His considered advice was "go back to optical and stick with it"!
So I decided that the time had come to abandon the LG's sound processing and just use the TV for the picture! I purchased a Denon AVR 1400H and some small speakers and then routed the Humaxes etc to it. The HDMI out of the Denon goes to HDMI 2 in on the TV with ARC enabled. Everything works, no audio or video problems, I even get Atomos 7.1 out of the TV. A happy ending for me, but admitting defeat in that LG will never fix their sound processing bugs.