As per the issue we could see, we are not fetching ip address from pf sense.
Lets focus whether we are sending DHCP request or not. You need to configure wan interface mode as DHCP only then we will get IP address from pf sense.
If you already configured it and if still not working, can you execute this command in the firewall :
diag sniffer packet <wan> 'port 67 or port 68' 6 0 a (where wan is firewall wan interface name)
can you execute this command in the firewall and share us the output