Not working ports

Hello. Recently i tried making a Garry’s mod listen server, but it doesn’t seem to work.
I configured the static ip, made the port forwarding(ports: 4380-4380, 27000-27050) and I have done this before, and it worked, but now that the router was changed (the new router is ZyXEL Prestige 660r-D1).
The port forwarding tool from portforward.com says that my ports are open.
The problem comes when I make the listen server, and when it’s done loading, I ask some of my friends to check what ip they see on my server info, and all of them see is 192.168.1.33:27015 wich is my static ip.
the console commands i use are sv_lan 0 and heartbeat, but it doesn’t seem to work either. i also tried giving them my external ip, but it still doesn’t work.
Any ideas of how to solve this problem?

Please help me! :slight_smile: