My suggestion is not to assume anything. Check the router port forwarding rules and make sure. Report back with the info and maybe we can help. You haven't given much to go on.
For VPN PPTP make sure port 1723 is forwarded and/or VPN pass through is enabled on the router.
Personally I think UPnP is very dangerous and a bad idea. I don't want any software having full control of opening ports on my routers. Remember the bad guys will have the same ability. I always turn it off on any router. All real firewalls don't even know about UPnP.
WPS is proving to be the same joke
(read about "this great idea"
Learn how to create port forwarding rules yourself on your router.
And don't forget to have fun.