Have no idea what happened to yours. Mine got warm, I unplugged them then a few os updates later, 1 stopped playing, and I could not update. 6 days, not a year (that’s a bit snarky) later I was able to manually reset and it is working fine
My theories are 1) bad power in house (low voltage, spikes, it was plugged into a splitter - the only one to be and the only one to have a failure) 2) thermal or humidity trip 3) iOS issue that didn’t see reset
why it took 6 days to reset a trip. No idea, that would tend to say humidity, not thermal. In any event, it didn’t take a year to reset
Apple support did call expecting an unhappy customer, but low and behold it was working fine. Sent diagnostics in. But after a reset so no idea how pertinent
my best guess is power issues in home.