Hi, Sorry for taking so long to reply. My licence exprired just after posting the problem.
When I ran show ap database i can see Flag R-c2 for this RAP.
The RAP is assigned to an AP Group called Default, it wireless LAN settings are set to use VLAN 1 and this is assigned to Port 3 which is NATed out to the internet.
Only one port is connected to our LAN, Port 3, and this is working for the LAN connection from the RAP.