Installed a new router RV180 at our school replacing a Netgear FVS336G.  works faster and better with one MAJOR problem.

port forwarding works from outside of the firewall to connect to resources.  from any computer in school (behind the firewall) I CANNOT CONNECT ( via RDP or HTTP to  computers or devices I need to.  obviously if I used the local IP address NO PROBLEM.  I raised this issue with CISCO support team and they escalated my ticked to LEVEL 2 engineers.  does anyone out there have any suggestions to help?

I provided packets I captured to CISCO support and no answer yet.