Hi - I may have a solution for this that'll work for you, but let me give you some context just in case it helps ...
I was originally using an HDR-capable 4K Panasonic TV as a video monitor, connected to my AV amp, and I was not using, nor interested in using, the onboard TV apps or receiving audio from that TV. It was a dumb display device, and I was able to connect to it using SkyQ at UHD 10 bit, Blu Ray also at 10 bit (4:4:4), and my PC, both at 4K 8bit and 10bit.
All devices went straight to the AV amplifier, the HDMI output of which went straight to the Panasonic. I flipped between inputs on the AV amp, and it all worked great.
The Samsung's onboard apps impressed me though, so I upgraded the TV to a 43" QN90B and decided to make use of eARC (on HDMI3 only) so I could play the apps back through my AV amp.
I've found that - counterintuitively - I needed to apply these settings to the TV:
Settings\sound\expert\Sound Output = AV Receiver(HDMI)
Settings\sound\expert\HDMI-eARC Mode = OFF
Connection\External Device Manager\Anynet+(HDMI-CEC) = ON
Input Signal Plus = OFF on all connections (* see note below)
THEN I needed to apply the following settings to my AV Amplifier (I use an Onkyo RZ-3100 - difference manufacturers may have their own terms for these items):
Setup\1.Input/Output Assign\1.TV Out / OSD\HDMI OUT = MAIN
Setup\1.Input/Output Assign\2.HDMI Input\[all devices] = HDCP 2.2
Setup\5.Hardware\HDMI\HDMI CEC = ON
Setup\5.Hardware\HDMI\HDMI Standby Through = Auto(Eco)
Setup\5.Hardware\HDMI\Audio Return Channel = Auto
Setup\5.Hardware\HDMI\Auto Lip Sync = ON
In this config, I have Sky Q running off the main box at 8 bit (*see note) UHD 4K, and the AV amp automatically changes input to a special TV setting for the eARC channel if I run any TV apps such as Netflix. I then hear the Netflix audio through my amplifier, and not through the TV.
However, upon closing that app and returning to the AV input source, the AV amplifier REMAINS on the TV setting, and although it makes no sense, I hear nothing at that point (possibly because the TV is now configured to receive its audio FROM the amp when its internal apps aren't generating sound).
I manually switch the AV amp back to the desired mode, and everything works as expected.
*Input Signal Plus and 8 bit Video with Sky Q : I've discovered that although Sky Q worked fine in my old setup, the new Samsung connectors on ANY of the HDMI sockets cause the Sky Q box to complain that the socket does not support UHD at 10 bit. I believe this might be due to cabling - I'm using a 7 year old 10m HDMI cable, which doubtless has not only degraded, but also isn't up to the latest specs. Whilst I got away with this on the Panasonic, the Panasonic itself is from a previous generation and I suspect that this is where the link is breaking.
So to summarise, as of right now, all works as it should, with the exception of 10 bit HDR.
I've ordered a new set of cable interconnects from Amazon, based on fibre optic tech instead of shielded copper. I'll post and let you know what happens.
FYI the cables can be found on Amazon by just searching for "fibre optic HDMI 2.1".
If you DO buy from Amazon, please use "smile.amazon.co.uk" and set up a charity for Amazon to give a percentage of your purchases to - they cover the cost so it makes no difference to your pocket. It's just something that over time can help a lot of people if you use that link as your go-to.
Best,
Marc
