D-Link DIR-655 :: Port Forwarding Doesn't Work From LAN PC?

Edit I've found a work-around. It's on page 2: [URL]

I'm having this really weird issue with my DIR-655 revB. I have some port forwarding rules set up and externally they work fine. However, if I try connecting to my IP address using those same ports from a computer within my LAN, it won't connect.

Externally, I can ping my WAN address and connect through forwarded ports. No problems. Internally, pinging my WAN address apparently works (just now is the first time that's worked for me), however I can't access any of my computers using the WAN IP and port forwarded ports. I can access them by going directly to their hostnames or LAN IPs.

Things I've tried:

-Disabling/enabling firewalls on all computers involved

-Disabling/enabling QoS engine

-Disabling/enabling DNS relay

-Disabling/enabling Advanced DNS

-Adding custom nameservers from Google and Comodo

-Restarting computers

-Clearing DNS cache (I use a dynamic DNS name which works externally but not internally. This gets the correct IP internally and connecting directly to the IP doesn't work either.)

-Modifying the NAT Endpoint Filtering settings

I have an external DSL modem connected to the router using PPPoE if it matters.

The weird part is that it works externally but I've modified all of the values I can think of in the config with no luck. I upgraded to the DIR-655 from a DIR-615 which had all these settings in it and worked fine (until it started acting up which is why I replaced it).