Same problem here.
Plus I'm new to LE. Not to linux or Kodi. I've used version 12 until yesterday. And many versions before that when digital out was just invented.
How do I configure the sound over SSH?
Where do I have to look? Can I debug wiht journalctl?
Where do I have to read in about the specifics of LE and kodi?
I fixed it:
"Are you using the hdmi port next to the raspberry pi's power jack ?"
Now I do. sound over hdmi works.