found one posting on reddit about a fire - but could not find confirmation that it was the m80 (that may or may not have been charging unattended at the time...) and one posting about one autofiring... not finding anything about them blowing up (the mods, not the firecrackers...) but I may just not be seeing it... from what i read, there was no indication of the humming being noted in either report, but again, I may just not be seeing it...
my personal experience with my m80s has been solid - no issues at all to date... I make sure I use a charger rated for them, and don't charge 'em unattended (or any of my batteries for that matter)
OP, I would suggest contacting vendor - sounds like above and beyond the humming, there may be an issue if it is not recognizing the chip for whatever reason... my m80s work fine for me in wattage mode, so I never bothered with updates to supposedly fix TC (since the TC is a bust)
hope this helps some - sorry to hear yours is acting wonky