Help portforwarding from an alias IP

We have been given 6 static IP’s, cable modem in modem mode, so IPfire has the second static IP for the RED interface, first static IP is the RED interface’s gateway.

Have added the other 4 static IP’s as aliases in the WebUI.

added a Firewall rule for
source address = static IP 3
NAT portforwaring
desination address = IP of web server
protocol = TCP, destination port = 80

this does not allow traffic in, firewall log shows port 80 to static IP 3 as DROPPED

has anybody got this kind of setup working ?