How can I pass broadcast discovery traffic across a BOVPN?

Good day,

I want to broadcast a discovery packet across a BOVPN. Below is the packet that needs to pass through the BOVPN that the Traffic Monitor is showing as being blocked:

2019-10-28 15:33:57 Deny 192.168.6.125 255.255.255.255 10024/udp 60752 10024 1-Trusted Firebox Denied 34 64 (Unhandled Internal Packet-00) proc_id="firewall" rc="101" msg_id="3000-0148"

We are not doing any NAT and the two networks are bridged via a BOVPN with Watchguards as follows:

LAN at office A:
192.168.0.1/20

LAN at office B
192.168.16.1/24

I have enabled broadcast traffic across the tunnel and have assigned helper IP addresses as per the documentation (172.16.0.1 on one side and 172.16.0.2 on the other), but it still doesn't work.

I can assign static IP addresses to both the transmitting device at office A and the receiving device at office B.

What happens is that when I launch the app at office A, it sends out the packet I included above and waits for responses for the hardware device on the LAN at office B. The hardware device is supposed to respond to the sending address with it's IP address so it can be discovered.

The app has no trouble discovering the hardware device if both are on the same subnet and local network, but does not work across the BOVPN.

Any suggestions?

Thank you.

Bill Sanford