No sound via HDMI except in Kodi application

Everything was working fine weeks ago and now I've started to experience the problem of having no sound. I'll give some background.

I don't have sound anywhere except for when I use Kodi. This means than when I play Spotify, Youtube, system sounds, the command say in terminal – no sound!

My output device in Preferences and in the upper menu and also in Audio Midi Setup is my receiver. It actually shows the correct device name and type as HDMI.

My setup is a Mac Mini, running Sierra 10.12.1 that is connected via HDMI to my receiver. The receiver has a HDMI connection to my TV and analog audio connection to my speakers. Video and sound have all been working but now I only get the video. So to reiterate, there is video in the TV but no sound from any of the speakers.

The weird thing here is that when I start up Kodi and play a movie I have sound.

The make it even more weird is that when I fire up Spotify and play a song I get no sound. If I now, while Spotify is playing startup Kodi and start playing a movie then the Spotify sound will also appear overlaid by the sounds/music from the movie. Once I quit Kodi I don't have Spotify sound anymore. I can see from the interface that the song is still playing.

If I change my output to Built-in internal speakers all sounds appear. Once I switch back to HDMI I have no sound.

Any ideas what is causing this? Any ideas how to debug this issue? I don't see any audio references in Console nor dmesg. Not sure how to continue debugging this situation.

Some things to note:

• The volume bar is greyed out in the menu. Even when I run Kodi and I have sound and I cmd-tab and check the volume bar it is still at 0 and greyed out
• Changing the volume from the commandline like recommended in this article has no effect.

Here are my Kodi settings