Glad you could solve it. As I said, what matters is the port 8384. If you had it accessible from your local LAN, then I assume it was already opened in the firewall. Might have to do with different zone definitions? Localhost is different from any other local LAN address, IPv6 vs. IPv4 might come into play, etc. At least on my Synology, enabling the firewall without any rules configured still allows the icon to show up while the service is running.