@Gblenn
HI
Problem solved.
The NUC has 2 Ethernet Ports as well as a Wireless Connection Capability.
I did not connect the wireless but it still came up as Connection port 1, so my attempts to configure were using a Wireless link, which was not connected and the first Ethernet Port.
I finally ignored the Wireless link totally, set up the WAN and LAN ports on the pfsense box as Ethernet ports 1 and 2 and lo and behold it works.
Thanks for all the help.
Cheers
Colin