UTM not seeing any traffic from new interface

I've added an addition interface to our UTM to setup a DMZ. I am unable to get the UTM to acknowledge any traffic on this new interface.

Clients in the DMZ network can communicate with each other, but cannot ping the UTM's interface IP, cannot get access to the Internet, and do not show up at all in the packetfilter.log

The existing Internal network interface has worked for many years without issue.

UTM interfaces

1. Internal - 192.168.0.1/24
2. Internet - ISP assigned public IP
3. DMZ - 10.225.0.1/29

UTM Configuration

• Interfaces & Routing
  • Static Routing
    • Interface route > DMZ Network (10.225.0.0/29)
• Network Protection
  • Firewall
    • DMZ (Network) > Any > Internet IPv4
  • NAT
    • Masquerading
      • DMZ (Network) > Internet Interface

I thought with the DMZ interface and Static Interface Route I would immediately see something, but no matter what changes I've made the UTM just seems to act as if the DMZ interface doesn't even exist.

Anyone have any insight? Am I missing something obvious required to allow traffic from a new interface to interact with the UTM?