Please take a look at this WIFI troubleshooting guide: https://support.particle.io/hc/en-us/articles/360052621274-WiFi-Connectivity-Troubleshooting-Guide
Also, would you mind downloading and installing Cloud Debug (link) onto the device? Upon doing so, please send me about ~10 minutes or so of logs produced by the device while it’s having trouble connecting with the Cloud.
The best way to produce these logs is with
particle serial monitor --follow in the Terminal of your choice (Mac - Terminal, Windows - cmd.exe, etc…) after installing the Particle CLI.
The Cloud Debug link provides installation instructions, but I’m happy to walk you through the process step-by-step if you like! Please note the de-installation instructions contained within this link.
Cloud debug will give me a lot of insight into the state the device thinks it is in - be it an issue with the network, a system or application firmware issue, a problem with the network coprocessor on the device, etc…, so your efforts in this this respect will allow me to resolve this issue as quickly as possible.
If it is preferable to keep your application firmware on the device at this stage of troubleshooting, you can alternatively follow the instructions at the article here (link) to gather trace logging while your application runs (again we request ~10 minutes). However, the Cloud Debug route is easier, more informative, and more objective.
After which, you can log a support ticket with the logs.