Gstreamer Configuration

I’m struggling to get the gstreamer integration working and hoping someone here might be able to provide direction.

I have Home Assistant 2021.1.1 running in a venv on a RPI 4.

My config entry is

- platform: gstreamer
  pipeline: alsasink

The tts file is created and can be played directly from the venv using

gst-launch-1.0 playbin uri=file:///tts/file.mp3 audio-sink=alsasink 

It can also be played from the venv using python like so.

from gsp import GstreamerPlayer
player = GstreamerPlayer('alsasink')
player.queue("file:///tts/test.mp3")

But attempting to call the media_player.play_media service like so

entity_id: media_player.gstreamer
media_content_id: 'file:///tts/test.mp3'
media_content_type: music

Results in the gstreamer showing that it’s playing and the appropriate title is shown, but without sound. Nothing in the logs.

I’m out of ideas on this one, does anyone have anything else to check?

Thanks