RE: Error M112 - Assistance with findings please?
Confirmed: The culprit was the element!
It is a quite common issue to damage thermistor or heater cables in the process of changing nozzles. It is a design flaw of the V6 hotend that those cables are so exposed and can be so easily damaged during nozzle change. If its only visible when printing PLA and you haven't done that in a long while, the damange might have occured already a while back.
A silicon sock is never a bad idea. It also keeps renegade plastic away from the heater block and cushions the impact of the part fan. That said, there is obviously something wrong here as the printer shouldn't pull the emergency break just because one is cooling 100% without a silicon sock. I'd just wait for the replacement heating cartridge and see if that solves the issue. If not, then the problem would have to be somewhere deeper but I would not waste too much though about that before you haven't replaced the cartridge.
RE: Error M112 - Assistance with findings please?
Cool, that you could identify and rectify the problem.
Mk3s MMU2s, Voron 0.1, Voron 2.4