Im experiencing the exact same issue. What’s interesting is that if I open an existing google_say mp3 file using the media player and selecting the path down to the file location (/config/tts in my case) the spoken text plays IN SYNCHRONY at all speakers is the selected group. If I play the same file using the Services tab, each individual speaker is a few milliseconds out of synch with the others. I’ll be glad to post all the different iterations of code I have tested without success.
The Sonos integration is one of my most useful and spouse appreciated features of HA, and has been nothing but frustrating for the past month. See this thread for additional insights: Problem with tts and sonos.
Anyone else having similar issues? Or a solution that actually works?
Sorry for the rant, just very frustrated that something that worked so well for so long, now doesn’t work well at all.