PureVPN/openVPN cant open ports

[Cliffb]

Hi All,

Got an issue I cant get my head round, I have a pureVPN account with static ip and port forwarding.

If i use the windows VPN client and connect out through my firewall (USG3, second port) once connected I can get to my web server via the vpn from out side my network.. Now what I wanted to do was have a cople of devices behind the VPN so I can get to them from the outside, this is where the OPNSense comes in.
I set up the VPN and that connects using the OPENvpm client in opnsense, and PCs on the inside can get out through the VPN. but I cannot for the life of me get even port 80 to come up as open coning in through the VPN to a web server.. I have deleted all my NATs i had as I think i was confusing the hell out of myself..

so currently my USG firewall gives a dhcp address to the opnsense WAN port 192.168.2.x the inside LAN of the opnsense is on 172.16.16.1 and the device running webserver is on 172.16.16.16. 

in the pure VPN portal I have allowed just port 80 to be NAT'd

should be simple, I would have thought to have inbound as openvpn and nat to the webserver with port 80 or any-any, but it seems nothing opens..

anything I need to do or missed, used to just being able to put in source and destination and the port and it working. not sure if its because the VPN is thrown in the mix too

thanks

Cliff