Hi @AFerg92, thank you for reaching out to us and welcome to the Sonos community. We really appreciate your time and effort in bringing this concern to us. Let me help you with this.
First, I'd like to isolate the issue so we can create a path towards resolution.
1. Are your Sonos speakers and Google Home Mini is in the same room?
2. When you command Google Assistant, which device responded to you (Sonos speaker or Google Mini)?
3. Have you tried commanding Google Assistance specifically like saying "Hey Google, play Spotify playlist in the Office."
Please refer to this article Help and tips for Google Assistant on Sonos to follow some troubleshooting steps to help you get the best results when using the Google Assistant on Sonos.
You can also submit a diagnostic from your Sonos system for me to check what's going on.
If you need help with any other information, please be sure to let us know.
The Sonos Community is always here to help.