Is DTS Passthrough possible via HDMI?

Volumio Information

I have DTS passthrough (surround WAV files) working through an SPDIF card.

However on another Pi on a different system I want to playback 5.1 DTS via HDMI.

To my surprise I’m getting the archetypal ‘white noise’ of a DTS stream which is not being passed through unprocessed (‘passthrough’).

Does HDMI passthrough work in Volumio? Does anyone have it working? I don’t care if the audio is passed as DTS or PCM so long as I get 5.1 at the amp…

Volumio Version: latest
Hardware: Pi 3B
DAC: none