Thanks for writing in! From what you’ve shared so far, it seems the protocols that configure port forwarding automatically are either not available or have failed. UPnP and NATPMP are not functioning in your router as Roon expects.
See if any of the following help:
Turn on UPnP on your router and try to run Roon's port forwarding test again.
Try to set up manual port forwarding in your router.
Make sure the IP/Port matches in any port forwarding rule you create.
Double-check to make sure you don't have any VPNs, Firewalls, or other network filtering software blocking Roon.
Check if your modem is in Bridge mode.
Restart your network hardware and update firmware.
While ARC can negotiate port forwarding via UPnP with a two-router setup, it’s sometimes more reliable to configure an identical port forwarding rule in the settings admin page for each of the two routers.
This rule should be TCP protocol and match the port and IP address from Roon Settings → ARC.