It’s a configuration of the software. I’m primarily talking about enterprise VPNs. Mose enterprises will configure the connection to make you part of the corporate network; and only the corporate network. Basically, all “local” traffic is blocked and all traffic must traverse across the VPN to the corporate network. In that case the machine isn’t local anymore it’s “living” on the other side of the VPN. In that case Roon will never work.
Other configurations only send the “interesting” traffic across the VPN and leave general Internet traffic and local traffic alone. In that case the machine sits on two network. It stays local for local and Internet but also has an “interface” in the corporate network. In this configuration Roon can work.
It sounds like your iPhone is “advertising” itself onto the local LAN so Roon sees it. But, it’s blocking the incoming connection from Roon server to configure that endpoint. Yes, you’re close, need to identify how to open connections on the local network.
- There looks to be a “multicast via VPN” pass/block setting in your Vigor. Try both options and see if that makes a difference.