My aunt did the exact same thing to my 5 year old at Thanksgiving, kept saying "she's just so shy" while the kid was literally reading out loud to herself. It's like they can't handle a kid who doesn't want to perform on command.

The new kid off the street making $2.50 more is wild, that would've sent me straight over the edge.

Tracking by brand is smart but check the batch numbers too. Same amp model from different production runs can have totally different failure rates, and if your supplier flipped to a cheaper batch last year that would explain why the timing lines up.