@jonpasc, @picsil,
I had started another thread earlier on this specific problem including all the logs, see Boron LTE - Permanently flashing green after running out of battery
@DJ_Volt has replied over there that this is a known, although rare scenario and the only remedy is to replace the board.
And no, there was no firmware flashing or modem upgrade. The device was in the field connected to a solar panel and battery. There was a long period of cloudy conditions, so it lost power. The next time I visited the device I saw the symptoms described above, permanently flashing green and generating the logs copied.
Following @DJ_Volt 's comment in that other thread, I have raised a ticket for the board replacement. I did not get more detailed explanation about causes of this condition in the ticket, although I didn’t ask for it. If you are interested, maybe @DJ_Volt can provide that.