Zabbix Proxy Between Two Firewalls

[spetrillo]

Hello all:

Site A: my home
OPNsense Firewall (192.168.1.1)
Wireguard S2S active (to site B)

Site B: my club
OPNsense Firewall (10.0.1.1)
Wireguard S2S active (to site A)

I have setup a Zabbix server on Site A. I have setup a Zabbix proxy on the Site B firewall, using the Zabbix proxy plugin. I can successfully run a port probe from Site B to Site A, using TCP port 10051, which is the Zabbix port needed for communications. When doing the same thing from Site A to Site B it fails. I have attached screenshots to show the successful and failed port probe.

I am confused as to why it works one way and does not work the opposite way. I would think that since its open in one direction it should be open in the opposite direction? Am I missing something here?

Thanks,
Steve