If you've been trying this for a week a number of causes might be at play here:
- Your router (or modem-router provided by your internet provider) is set up not to be compatible with 802.11g (which at least is the mode that the Oak switches to during set-up, not sure if it automatically switches to N on an N-only router)
- Your router is set up in a way that is incompatible with the Oak's firmware.
At least one of the above is currently my issue. Both at work and at home I've been able to see the Oak in the DHCP client list of my router, but it does not stay connected. When I use my phone as a Wi-Fi Hotspot everything works great. I hope there is some kind of firmware tweak (maybe even from the existing ESP8266 community) that improves the WiFi compatibility of the Oak firmware. My guess is that it doesn't play nice with devices that also do Wireless AC. Thus far this is the pattern I'm seeing. (And yes, I know Wireless AC is not on 2,4GHz and the Oak does not possess 5GHz capabilities).
Have you tried to connect through your phones hotspot instead of your regular WiFi network? What were the results?