No connection to RCON outside of home network

So I now have a new modem, I've setup a new server and its up and running. When I use admin apps or programs on my pc or phone it only connects when on the same network as the server but as soon as I use my phones network it cant connect. I've tried setting it up on a friends pc and they cant connect to rcon.

both ports seem to be open as there isnt an issue with the server showing up in rust or people connecting. just an issue with rcon.

anyone have any tips or ideas?

 

I think you are right, the thing is, I turn off the firewall on the router and PC and try and it still isn't working. On canyouseeme.org it says the port is open... I'm out of ideas.

 

Yeah I do, I've had this server running fine for over a year until I had to replace my modem. The first modem I got after days of research had known port forwarding issues so I bought another one, the same model as my first one that worked.

I have it set as start port: 28015 end port: 28016 protocol: both and obviously the servers IP.

 

Ok so today I'm seeing port 28015 is blocked but 28016 is open.