I had a problem with cards getting demagnetised, for a long time. IDK if i just have different stuff in my wallet now or what, but it happened to me for years and then stopped happening, years ago.
Cashiers would always try rubbing it with a plastic bag, which frequently worked, which makes me think something something static electricity something magnets??
Well, the best part of 5 minutes is that first 30 seconds; the rest is kinda boring. So maybe they pissed themselves for 30 seconds.