Well there’s been no formal recall 
, and only bambu really has the incidence rate , but some people’s AC boards have failed in the same way w/ a molten thermistor. Gets so hot the case plastic deforms, kills itself as thermistors are want to do. The replacement PCB is differently designed than what was in it.
megaThread here if youve got a cup of tea: A1 Fire risk due to thermistor overheating