Hello @ARD,
Thank you for the update.
Please note that UPnP is not officially supported in Roon. However, there is a community extension that may help with your current setup. You can check it out here:
rooupnp: Finally a Roon extension for UPnP streamers
Keep in mind that this is not an officially supported solution, and if you encounter any issues with the extension, you should reach out directly to the topic creator for assistance.
Let me know if you need further help!