Particle Boron that connected last night now permanently fails ever to connect to internet / flashes green

I want to make clear that this issue is distinct and separate from the previous, distinct Boron-malfunction-disaster issues I have experienced about which I have made threads.

This issue is not:

  1. Boron was working then was recovered dead with no LED and resets resulted in system crash even on Tinker within 1 second;
  2. Boron on 2.0.0-rc1 fails to reconnect after losing cellular; or
  3. Power-switching VUSB causes Boron to fail to reboot, even though fully powered, ostensibly due to minor pin leakage input current, causing the Boron to be totally and permanently disabled until the entire circuit is manually power cycled.

This issue is different.

A Boron I had connecting last night, ID e00fce68ad1b178791daf14e, now totally fails to connect to cellular.

The antenna is attached and it is in a spot where other Borons are connecting.

I left it up to 2 hours - flashing green with zero exceptions.

I reflashed v1.3.1-rc1 system part 1 and tinker. Same result - no connection.

Then I flashed 1.5.0 system part 1 and tinker. Same result - would not ever connect.

Then I downgraded again to 1.3.1-rc1. I also tried reflashing the bootloader over serial which failed with the message, ‘Error writing firmware: unknown message’.

Now it is powered and still eternally failing to connect - green flash.

The infuriating and inexplicable thing is not that Particle Borons don’t work. Rather, the infuriating and inexplicable thing is that they work, then, randomly, they suddenly don’t work. They first work giving you a false impression and reliance upon their functionality, then this happens.

The cloud interface shows it was connected last night, “Aug 21st 2020, 7:48 pm”, with no problems. Same place (inside my house doing testing related to one of the other threads I made).

Now it is never connecting. It is not crashing into a no-LED apparent brownout state 1 second after boot like my other thread. It is staying up with the flashing green never-connect state using bare, clean Tinker on both 1.3.1-rc1 and 1.5.0.

Does anyone else experience this?

Are there demonic spirits attached to the Particle Boron which explain why it suddenly and randomly fails? It certainly seems like it, given how unpredictable and fickle this product is. I can’t explain how it was connecting last night but not now. Bare USB into PC - no external connections. Perfect cellular and power.

Does anyone else witness the catastrophic reliability problems I do with the Boron?

Is there something I can do to recover this Boron and make it connect again? SIM is activated and well below 50mb data limit.

Thanks for the help. I am trying to give Particle every chance I can give. At this rate though, I believe I will be parting ways with the Boron for a solution that actually works.