Can't connect to the NVR on external LAN through my LAN with XG firewall

Iam using the XG 125 as firewall in my office. I cant connect to a Dahua NVR using the Smartpss sotware from my office LAN.

The NVR on a different network different location and is open all desired port inside the NVR. I can connect with ddns service like "example.dahuaddns.com" But i cant connect by using the software.

Open ports in NVR are http80,tcp3777&rtsp554

"Without using firewall i can connect the NVR from my office LAN by using Smart pss"

Based on my trouble shooting it's the firewall that is blocking the connection.

Please give advice, will be much appreciated