I was having an issue that sounds like setup #4 (from the Known Issues, where Argon devices do not connect to wifi). After many failures and no little frustration I turned off the VPN service I use and lo-and-behold it worked almost immediately that time. This also might have been a factor during part of my Xenon setup… But not sure on that.
Anyways, a possible avenue to look at, or for users to try might be whether a VPN is enabled or not.
What VPN service? Is is a corporate VPN or one of those free ones used to mask your internet presence? Do you know if the VPN dishes out an IPv6 address? (If using windows, you can do an ipconfig /all in the command prompt to view.)
Another potential issue is that the Argon uses UDP to communicate with the cloud. Normally, firewalls open up a temporary channel to get the packets back from the cloud by UDP (dynamic port mapping), but if a particular firewall or VPN service does not, then that will make it impossible to connect to the cloud.
The service I use is Windscribe. Do not feel my ISP needs to know everything even if I do not surf anything I would worry about. Plus it has really helped kill the personalized ads that were getting downright scary.
It does not appear to use IPv6 (from my phone info at the moment, same phone I use the Particle app on).