go into the webadmin (advanced/device settings and chose core in the left pane) (after you have set the wlan) and check if the card is listed in the box at the bottom (ra1)
If it is not, then add it (you can pick up the syntax from the other NICs listed) but it goes like this
ra1,dhcp,255.255.255.0,10.0.0.1,10.0.0.1|eth0,10.0.0.100,255.255.255.0,10.0.0.1,10.0.0.1|eth0:0,10.0.0.10,255.255.255.0,10.0.0.1
Green text is the gateway (10.0.0.1 is the gateway for me)
Red text is the assigned IP, DHCP specifies that this NIC get's it's IP from the DHCP
255.255.255.0 is the subnet
If you have to add the card, be sure to save. then setup the car in KDE (again), then reboot