Our new Sonos integration is now live that helps fix this issue!  Please take a look at this article about grouping Sonos Players for more information: https://yonomi.groovehq.com/knowledge_base/topics/how-do-i-group-my-sonos-speakers

If you are having issues with playing Favorites or Playlists on Sonos speakers via a Routine, we are aware of a limitation where the Play Favorite / Play Playlist actions each run individually. As a result, you may get different songs that play out of all of them, or they may not be completely synchronized.

For this to work as expected, you will need to create a multi-zone group from your Sonos app, and then just run Play Favorite or Play Playlist on the main speaker in that group