@ScruffR I emailed Particle support on the 24th Aug with a link to one of our threads asking if we could have input from Particle team - as we are working on a large commercial project and need assistance.
The response from Rick was there is no definitive answer, to check the common known issues and to consider a watchdog timer (a watch dog-timer itself isn't solving the issue).
I then Emailed back the following:
'You mention you guys can't troubleshoot individual projects, but I would like to state this is a high profile project, with Lend Lease - one of the largest construction firms in the US. We are keen to get past the prototype stage - so please ensure that the relevant people at Particle are aware that we have technical issues that we need resolving to be able to push Particle out across their sites. Until this issues is fixed we can't move forward with Particle.
To which I go the response that Particle aren't able to give free support.
I then replied to that Email on the 25th of Aug asking for an estimate of how many hours Particle may need and how I can go about making the payment to Particle (which was quoted as @$200 per hour).
I still have not had a response to that support payment info request Email, that was sent on the 25th Aug.
It does seem strange that we have got a few threads open and had no direct contact or reach out from Particle. We are not tinkering around in a bedroom with little consequence, we have Particle out installed on an industrial environment and the project is about to be wrapped up in terms of using Particle if we don't make some fast progress.
We are not saying the issue may not be related to our code or hw, we are not sure what is causing it, it's just we have explored a number of avenues (our selves and with the help of the forum) and it has not been resolved. There seem to be one or two others also getting the cyan LED lockup.