Going to pitch in some info since i was also confused with the noise.
It does seem to appear after you do a calibration or device self test and the new noise has also caused some damage to the screws that hold the fan inside the housing. My current fan currently doesnt have the two screws holding it anymore since they snapped off during the bed leveling sequence.
And i noticed the noise seems to revert back when i changed the nozzle. Not sure if its the nozzle change that reverts it or if its when pulling out the cables.
Same exact issue after updating FW. P1S with AMS. It always made a noise like this but the intensity/length is much increased. Please help!