Unable to port forward from WAN

I have an AR300M v2.25 with WAN port connected by cable to LAN port on my DSL modem. AR300M wifi connection via static IP to another device, with port forwarding set up in Luci firewall. Using the LAN, I can connnect via port forward to the device. However, Using the WAN via gl-inet DDNS, I cannot. From the WAN I can only connect via port 83 to AR300M. Access control page shows Upnp service open and Access Port redirected. What do I need to do to enable port forwarding via WAN?
Thank you.

I got your ticket and replied you.

Please check if port forward has been correct set up.