I’ve had two “high quality" Samsung uSD cards spontaneously die, taking all my information with them. These are devices of extraordinary complexity. There is no guarantee with any digital media. I always tell people that if they have critical information on a single digital device, they should assume it’s already gone. Flash memory works perfectly until it doesn’t and then it’s gone permanently.
The solution is inconvenient but it works.
BACKUP! BACKUP! BACKUP!