I have photos backed up on some WD hard drives from different periods in the past decade.
I always made sure to format them with my laptop ahead of using them. And I’m using a MacBook.

I just opened up one of the drives and I’ll open up a folder and there are no photos where I had photos before.

Does that sometimes happen with time?
Are external drives not reliable?
Have a placed a magnet too close to them? Or some external factor possibly cause it?
Anyone else experience this issue?