Impossible to get Roon Arc at work.
From suggestions of similar issues, I installed port forwarding.
See error attached error messages to see the difference.
I hope there would be a solution.
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?
This user has a similar router to yours - I’m hoping the GUI for the KPN 12 is similar to the V10 listed in your own description.
Provided you also share an internet service provider and have related account implementation in place, I recommend you attempt to create a manual port forwarding rule in the Access Control section of the router web GUI as they did here:
Please let me know if this helps. If not, please provide the details kindly requested by our helpful moderator above, and we will proceed from there. Thank you!