Can you provide a bit more information around the Node Icon, and how it’s connected to your network/server? Please set up a direct ethernet connection to both and see if you run into the same issue.
If you haven’t yet, I’d also stop Roon Server from running, and power cycle the machine. Afterwards, if you’re still not seeing the Icon under Roon Ready, please use the directions found here and send over a set of logs to our File Uploader?