Hey, it should work if you have no connection to the internet. Perhaps you connected to another source - LAN, phone network?
I'm not sure what went wrong, but it should work when no Wi-Fi connection is available.
That's great to hear, hopefully you'll stick around for more jams :)
BTW there are a few more big jams, you don't have to wait for the next GMTK one.
Take a look at Ludom Dare, and Global Game Jam. Their next jams will probably occur before GMTK 2024, and they're with many people too - great place to get some nice feedback and recognition for your games.