Multi-room music alexa custom component

I use the following custom component quite successfully for lots of things;

I have just tried to play some music with a target of the multi room group (setup on alexa app) but it doesn’t play;
https://github.com/custom-components/alexa_media_playe

service: media_player.play_media
data:
  media_content_type: SPOTIFY
  media_content_id: Send me on my way
target:
  entity_id: media_player.everywhere

It works fine if a target a specific alexa, feels like it has something to do with issuing multiple spotify streams perhaps?

Can’t seem to work it out, anyone done this sucessfull?

Sam

Did you ever solve this problem and can play local mp3 files from Home Assistant?