Dual WAN interfaces to DMZ & LAN interfaces

Good day all,

I am running Sophos XG Firewall SFOS 17.5.3 MR-3 as a VM. There are 4 x Ethernet adapters dedicated to Sophos. 2 x WAN, 1 x LAN and 1 x DMZ.

IPs as follow:

WAN 1 = 28.124.156.5

WAN 2 = 28.124.156.6

(both on same gateway which is 28.124.156.1)

LAN = 192.168.0.1

DMZ = 10.10.10.1

Here is what I am looking for:

WAN 1 --> DMZ (WEB SERVER)

DMZ (WEB SERVER) --> WAN 1

WAN 2 --> LAN (DOMAIN)

LAN (DOMAIN) --> WAN 2

What is working so far:

WAN 1 --> DMZ (WEB SERVER)

DMZ (WEB SERVER) --> WAN 1

What is not working:

WAN 2 --> LAN (DOMAIN)

LAN (DOMAIN) --> WAN 2

If I include LAN (DOMAIN) to the DMZ (WEB SERVER) firewall rule, it works fine. However, it is using WAN 1 IP which is what I do not want.

Any expert ideas?

Thank you.