Thanks for the suggestion, holmes4. And thanks also for the info on the futility of hiding the SSID (I never knew that!).
I did accidently used the same SSID on the 505 as with my NETGEAR router modem. But it caused a problem when my laptop linked onto the 505 (with no internet access) and not my NETGEAR router modem (which has internet access). It seems the 505 just acts like another wifi network at that instance.
But, since its futile to hide my SSID, then I'll try back the original instructions as per the User Manual. Will keep you updated.
Thanks