Firewall/NAT

I have inherited the firewall so I am new to it and its settings, it was all was working well until we added a new computer to the LAN. The firewall was set up to NAT RDP access. each user is assigned a port to add to the remote access address example: mail.domain.com:3111
on the firewall NAT: it is set up as, if=WAN, Proto=TCP, Ext, Port Range= 3111, NAT IP= 10.0.0.118 Int, Port Range= 3389

but when we try to RDP we get a connection fail, not sure if it is the settings in the firewall I set up or the PC? I have the Remote desktop option enabled and Domain admin and user have remote access.

I am looking at the pc as the problem but don’t know how to test the firewall to be sure its not the problem. (or my config of it)
Inside the firewall I can RDP into the PC but not from outside the firewall.

Thank you for your time.
Mark

It needs both a NAT and a firewall entry.  Do you have both?