@mgattmch
It took me a while…
We have the 65” OLED.
The #2 input (in the middle) is the eARC. I have 3 input HDMI ports.
Yes it is an input, so the Audio Reverse Channel is like Pinocchio when he was becoming a donkey… as that the sound goes out through the input.
Linguistically it makes little sense… but it works.
I/You also need(ed) to enable eARC in one of the menu areas.
It took me an hour of dickin-round to get it going.