Thanks for sharing your report with us, @Alex_Simmons!
May I ask that you please provide a brief description of your current setup using this link as a guide.
Make sure to describe your network configuration/topology, including any networking hardware currently in use, so we can have a clear understanding of how your devices are communicating.
Can you confirm that you’re able to stream the Google Home Mini from the PC client outside of Roon?
Thanks,
Dylan