Trouble accessing JRemote/Panel/Media Network from outside your LAN is almost certainly Firewall.
You need to make sure you do
two things:
1. Port Forward the TCP port MC uses through your NAT Router to the machine you use to run MC (or configure Full-NAT for the Port if you have that option on your firewall, but you probably don't). This will be simpler if your MC-running-machine has a static IP address (so that it doesn't change if you have it offline for a while and then breaks your port-forwarding rules).
You have to do this because when outside your LAN, the attempts to access your server come into the ROUTER, not directly to your computer. A NAT Router doesn't know how to deal with those connections, and has to be told where to send them. If you
don't tell it where to send them, it "drops" (ignores) them.
It isn't really possible to write instructions for this, because all Routers implement this in their own way. But, this is kind of a decent general guide:
https://www.lifewire.com/how-to-port-forward-4163829If you want instructions specific to your model, Google search: port forward BRAND MODEL
2. Open the same TCP port on the Windows Defender Firewall as described here:
https://www.windowscentral.com/how-open-port-windows-firewallThis is a bit simpler than Port Forwarding because you don't need to tell Windows where to send the packets, but is otherwise the same idea. If your computer receives a packet from an external subnet (outside of your LAN) it will, by default, drop (again, ignore) the packet. So, you need to make a rule in the firewall that specifically says "except for these packets, when they come in on this specific port, let them through."
This isn't needed for communication inside your LAN because the Defender Firewall's automatic application-based exceptions will automatically allow these connections from your computer's subnet (any other connection on the same LAN). But they don't trust external IPs without a manually added rule.
Notes:
* MC does not use UDP, so you don't need to open/forward UDP packets.
* You can skip #2 if you turn off the Windows Defender Firewall (which is a decent way to test if that side is blocking the connection) but you shouldn't do that, and should just open the port.
* Many routers have a system of UPnP based automatic port forwarding. MC does not work with these systems because they're based on constant use and the internal application "asking" for the connection. These systems are also WILDLY insecure, and you should find the settings for the system in your Router (while you're in there setting up the Port Forward rule) and just turn the whole thing off.
