Recently (with firmware v84) my openSPOT2 said it couldn't connect to the Internet.
The WiFi connection was great and I could connect to the device just fine. This was not a WiFi bandwidth or channel problem.
The device said it got an IP address etc. from DHCP and my router said it had a good connection to the device.
Other devices on my network are fine, and I tried factory resetting the device (pressing the hardware button for more than 30s).
I also tried telling it to use other DNS servers than what's provided by DHCP.
I tried downgrading it to v83. I couldn't find any older firmwares to downgrade to. It looks like the image server only keeps the current stable, current beta, and previous.
The logs suggested it wasn't talking to NTP or anything else successfully.
Then I manually upgraded it to v84 again. Now it works. I don't know if this means the firmware was corrupted and manually downgrading and upgrading again fixed it. Maybe it means some service was offline that it uses to know if it can connect to the Internet.
In any case I wanted to post in case someone else had a similar problem and this might help them.