What's the model number? And what do you mean by " WAN ip shows different to my Public IP"? Is the WAN IP the public IP or private IP address?
Try to access WAN IP:16000 from external network, will it work?
If that works, then it should be the issue with DDNS settings.

Shield101 wrote

What's the model number? And what do you mean by " WAN ip shows different to my Public IP"? Is the WAN IP the public IP or private IP address?
Try to access WAN IP:16000 from external network, will it work?
If that works, then it should be the issue with DDNS settings.

Model number is TL-WR1043ND v4

My public ip is 180.148.214.x
My wanip is 171.16.211.x (PPPoE)
My private ip is 192.168.0.x

Actually I am trying to connect my game client ('voobly': to play Age of Empires) that suggest to forward port to 16000. I did port forwarding to 16000 but the game server was not connecting. When I check with 'Simple Port Forwarding' software it says the port is not open. Then i called my ISP and they fixed it. Now the software says the port is open. But still I cannot connect the game server. My firewall/antivirus is turned off. When I use VPN, then I can connect the game server. Don't know whats going on.

Model No: TL-WR 1043ND (firmware 3.16.9 Build)
Public IP: 180.148.214.x
WAN IP: 172.16.211.x
Private IP: 192.168.0.x

I am trying to play an online game (age of Empires) with a game client (voobly client). The client suggest to port forward 16000. When I checked whether the port was open or not, it says the port is not open or not reachable (I used 'Simple port forward' soft). Then I called my ISP and they fixed it (as they said). Then i checked again and now the software says it is open. But I still couldn't connect with the game server. But when I use a VPN client, the game server gets connected, which means something is going wrong with the network). My firewall/antivirus is turned off.

Please help.