Would you mind retrieving the Cloud Debug logs? 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.
There are 2 ways to retrieve Cloud Debug logs:
If you are using Chrome, Edge or Opera, you can try this convenient browser based retrieval (https://docs.particle.io/cloud-debug/). You can flash Device OS (including bootloader and soft device) and the cloud debug firmware right from your browser with no additional software required. Once generated, you can view the Cloud Debug logs right on the web page, with the options to copy to clipboard or download it as a file.
Alternatively, you can download and install Cloud Debug (link) onto the device? Output the logs 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.