castSoundboard (Nest Mini) not working

Questions & Help
,
1

I’m trying to make a simple script to use castSoundboard on the Nest Mini.

What i got:

Homey.flow.runFlowCardAction({
    id: 'homey:device:ID:castSoundboard',
    args: {
      sound: { 
        name: 'scenic.mp3'
        } 
      }
    });

I can hear the speaker connecting (it makes a connection sound when using the castSoundboard flow card for examnple, followed by the audio from the selected file). But I can’t figure out what I’m doing wrong. Since it won’t play the actual file.

Filenames are correct (when using the cards in a flow it works).
I assume I’m missing something in the args?