Motorola SBG6580 Passthrough Limits Connectivity

Motorola SBG6580 Passthrough Limits Connectivity

I am trying to set up a VPN server on Windows Server 2012. I am able to
connect to the server locally but not from outside my network ( using my
WAN IP address ). The internet on the server works fine until I try to
enable passthrough on the router/modem. I enter the MAC address of the NIC
on the server and enable passthrough and when the router restarts I no
longer have internet connection getting a "Your computer appears to be
correctly configured, but the device or resource (www.microsoft.com) is
not responding" from the troubleshooter. But when I remove the MAC from
passthrough I get internet again. Why is passthrough disabling my
internet?