Does the ARC page in Roon Settings display “Ready” or “Not Ready?” If the latter, what is the diagnostic message presented? This will help us diagnose the port forwarding blockage and identify troubleshooting steps.
If the page reads “Ready” but you’re experiencing intermittent network connection, then do you have any VPNs, VMs, or additional network interfaces on your RoonServer machine? ARC retains sight of a single pathway to RoonServer - if the machine switches pathways to the internet, ARC can lose sight until restarted.