So you’re not “double NATed” then, right? If that is the case, then your pfSense is getting a public IP address straight from your ISP, your pfSense device is directly exposed to the Internet, and your pfSense is pushing a 192.168.X.XX address to your Edge switch, which you have then subneted (192.168.166/192.168.171) into VLans for your devices, right?
In my case, from my pic, I am double NATed. My ISP sends a public address to my fiber modem, and then my fiber modem, via DHCP, gives my pfSense box an IP address of 192.168.2.1. My pfSense network, which is a different subnet, is based on 192.168.5.X addresses (no Vlans) from the pfSense. So, I have two subnets: 192.168.2.X and 192.168.5.X.
So, when the Edge router is in production, you have Internet, whereas with the pfSense device, you do not. What then is the WAN/LAN IP addresses of the Edge router and the pfSense device when they are connected to your Fiber modem?