I wanted to check in on this thread to see if you were still running into connection issues with Arc? After reviewing the information you’ve provided, it appears that you may be running multiple NATs in your setup. Please review our help article on the subject, and let me know if you’re able to solve the issue through the steps provided.
If, after going through the above, you still experience issues, please provide the following information:
Who is your internet service provider?
Please list the make and model of your modem and router?
Do you have any additional network hardware, like additional routers or managed switches?
Does your network have any VPNs, proxy servers, or enterprise-grade security?
How is your Roon Core connected to the internet?
You may need to reach out to your ISP to ask about getting a static IP address as well, if none of the above helps.