Despite Roon Core being accessible to ARC, I cannot get a network connection, even sitting in front of Roon Core. There is no error message and port forwarding is established.
My system: Roon Core on MacMini, Ethernet connection by Lan with 1000 mbit/ sec download, no VPN, network switch or blocking firewall.3000 tracks in library. Arc on iPhone 13.
Port forwarding help link not helpful for me.
Poor Connection messages even on home wifi and although ARC setup works in principle can usually be fixed by resetting the ARC app from Home > Settings. Sometimes, an uninstall/reinstall of the ARC app is necessary.
However, you will lose any downloads in ARC in either case.