Port Forwarding not working when default gateway is different.

[shubham.368]

Hi All
I am having a topology like this.

So from here, I am port forwarding a random port for my services to my internal network I am running OSPF with different networks running on this topology you can see I have two WANs with different service providers but I have one static IP and one DHCP IP so when my default gateway is set to static IP I can reach my service from internet I had checked from ping.eu it shows open but when the default gateway changes to the DHCP one it shows port is closed I am using FRR OSPF in PFSense so on the static IP I am using Pfsense and Firewall 2 is from different vendor so my problem is that when I change the default gateway my port is closed so can anyone help me with the solution.
Thanks In Advance