Port forwarding for plex through VPN

Hi, I am attempting to set up port forwarding for my plex media server so I can access from outside of my home network however I am running into some issues. Plex says I am successfully signed in but it cannot reach my server from outside of my network.

Here is what plex says in their help section about port forwarding;

Forward the Port in the Router

In order to forward a port for Plex Media Server, you'll need three main pieces of information:
WAN/External Port: Port 32400 is default, but you can generally use any available port in the 20,000 to 50,000 range.
LAN/Internal Port: This will always be 32400.
IP Address: The local IP Address of the computer running the Plex Media Server. This is what you did above.
Important: While you can choose any valid WAN/external port number you desire, the mapping for the LAN/internal port must always be 32400.

I use privateinternetaccess.com for my VPN and have set up my port forwarding with them although the port that they specify I am using is not the same as the 32400 required by plex.

I am using a linksys E3000 router and thought based on the information from plex above that I should specify my internal port as 32400 but I would use the port that my VPN assigned as my external port. (I have also tried combinations of same internal/external port 32400 and internal/eternal port that I was assigned by my VPN but nothing has worked so far). On the plex support forums I read that the protocol should be TCP but I have also tried UDP and "Both" in my router settings. Any ideas? Thanks guys.