Just got my A600GS from the post office tested it briefly.
There is no HDMI audio here either. Its connected to a LG TV, I use the same input as I used previously with my Pi4 that did work with HDMI audio.
Change the resolution to 1920x1080 50hz but this did not help for me. I also tried setting it to 1280x720 50hz, but then all I got was a black screen.
