Google Assistant Spotify/Media Playback

For the last two years, I’ve been running a Russound multizone amp with Google Chromecast Audio’s as source devices. Each CCA is in multiple google home speaker groups and I use some automation in HA to detection the group playing and turn on the zones in the multizone amp. It’s been rock solid since I implemented it. I have a few google home devices where I set the default audio playback device to respective speaker group and use “Hey google, play music” and I’d have my Spotify music playing in the room. Last week, this voice part stopped working completely. Google said it worked but nothing happens. If I manually use the mobile app voice control it works, or if I set the default audio device specifically to a CCA device it works. What is broken is using voice command to cast Spotify from a google voice input device to a speaker group. On my home hub I can cast to the speaker group manually through the UI however.

I’d like to get a voice workflow that would allow me to do this, ideally with the existing Google devices. Is it possible to use voice commands to send to HA and then automate the media playback with spot cast or something? I wouldn’t mind getting new audio source devices but from what I’ve seen, only google speaker groups allow a single device to be in multiple groups. Apple and Sonos only allow a device to be in one room/group.