Hello @Henry_Svendblad ,
Welcome to the forum and apologies for the delay in getting back to you here. So we can better assist 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.
How are the Sonos devices connected to the network? Are they on the same subnet as the Roon Core? Any VLANs in use in your setup?