Steve, at what stage of the process is the WiFi connection failing? When the clock initially comes up as an access point are you able to connect to it and enter the credentials for your home network? If so, what happens after that? The router shouldn't really matter (unless you have some sort of MAC address restriction turned on in it), I mean WiFi is WiFi unless BT has done something totally non-standard, in which case you probably couldn't connect with your phone or anything else.
Look into it later when the dust is clearing off the crater.
How do you know that you are not connected? Is it showing a wrong time?
Does the left hand red LED light or not? If it lights, that means the clock thinks it is connected. If the red LEDs are on, just leave it for a couple of hours and it will pick up the first time sync. After that it should not show this problem any more, because the RTC will have been set up after the first time sync.