It looks like you’ve gotten some guidance on how to continue. Here’s our form response for this issue with some things to consider.
Thank you for your patience while we’ve diligently worked to reach every request for support with port forwarding. The diagnostics you’ve provided suggest that your Core is having difficulty reaching our servers. There are several independent factors that can cause this error, so we recommend double-checking the following to initiate troubleshooting:
Is your router firmware up to date?
Do you have any VPNs, proxy servers, or enterprise-grade security on this network?
Are you experiencing any issues with Roon Remotes, or other apps on your local network?
If you continue to experience difficulties, please tag the support team and include the following information:
What is the make and model of your modem and router?
Do you have any additional network hardware, like additional routers or managed switches?
Who is your internet service provider and what is your geographic region?
Is your Modem configured in Bridge Mode so that it operates only as a modem or do you have the ports forwarded on both?