Where did the missing magazines go from my magazine rack?

I decided to craft a magazine rack to go next to my Bobblehead Stand and waste an hour displaying all the magazines I've found in the wasteland (the wooden magazine rack, because getting them into that was only extremely hard but getting them into the metal one seemed to be impossible!)

After many more hours of play I noticed that the magazines were not where I left them, several had fallen down onto the bottom or onto the floor, and some where missing completely. I picked them all up and put them back in the workshop, but I'm missing Hot Rodder, an issue of Total Hack, one issue of Taboo Tattoos, two issues of Tales of a Junktown Jerky Vendor, and at least one issue of Wasteland Survival Guide (I can't remember how many I have found). I also thought I was missing one part of "View from the Vault" but that had just fallen behind the magazine rack, so I found it when I moved the rack.

I know I don't lose the perk if I lose the magazine, and I don't need the caps I could get from selling them, but it's annoying that after wasting an hour trying to make my settlement look nice with a magazine rack I end up losing them.

I assume the magazines got knocked out of place by an idiot settler stumbling around trying to find their bed, but where could the missing ones be?

Is someone likely to have picked them up?

Could they have gone back to their original spawn points? (And even if not, could I find a second copy by going back to those places?)

Is this just another bug in this flawed but still great game?