Ok. I posted a response with a video attached to show what was happening. Perhaps the post with video wasn't accepted as I can't see it either.
Basically I tried the switch method. Trying the URL failed.
The web browser came up and as I was sonfiguring WiFi it disappeared and I can't get it back.
The video shows both red LEDs lit. Colon leds flashing alternately and the neopixelLEDS flash slowly red and the time is +1 hour for GMT
How far did you get with configuring the WiFi? Were you able to select your network AND enter the password before you lost the connection? I'm guessing that's what happened because what you go on to describe about the LEDs sounds like it's connected to your network and working right.
So... if it really is on your network, you can try (in browser):
This will work of there's something on your network that is functioning as an mDNS responder.
If that doesn't work you can use the button to get it to show you its IP address on the tubes. See Page 8 of the
(not the Construction Manual). Then enter the IP address in the browser. For example, if the clock tells you it is 192.168.001.199 you would enter: http://192.168.1.99/
One of these techniques should work.
Look into it later when the dust is clearing off the crater.