Watchguard Configuration multiple Firewalls

I now have 2 ISP’s, and 2 Watchguard firewalls. Internally the interfaces have the following IP’s Firebox #1 xxx.xxx.xxx.1 and Firebox #2 xxx.xxx.xxx.2 I also have a DMZ that both firewalls are connected to with interfaces of Firebox #1 xxx.xxx.xx5.1 and Firebox #2xxx.xxx.xxx.5.3

If I set an interal PC gateway to Firebox#2 and ping the DMZ server which has the gateway set to Firebox #1 it fails. I believe Firebox #1 see’s the traffic as “spoofed” since it never passed through it.

This is not a policy configuration error since I was able to ping the server if the gateways were set to the same firebox.

Not sure how to circumvent this.

Any help would be appreciated…!!!!

Thanks!!!!