I see that some of you have the same problem as I but I could not find a solution in those posts. Hope someone cam help.
My TV Q80T and my Soundbar Q70T do not work together. They are connected via original HDMI cable through eARC port. Sound from TV works, sound from Soundbar works, but when I switch on TV+Soundbar the sound only comes from the Soundbar. Sometimes the sound comes from both for half a second or so and then TV sound disappears.
support does not know what to do. All they did was a full service reset of TV and reset of Soundbar which obviously did not help.
Software of TV and the soundbar are all up to date