I just built my first camp in adventure mode, but whenever I pass time by building or traveling the books and artifacts I have in containers and pedestals tend to get strewn about on the ground outside my hut. Interestingly it seems like the only ones that do this are all from the same collection of items I found all just lying on the ground all over the place about 30 feet from a fortress. The collection includes like seven books, an artifact mug and an artifact copper crossbow. First, why are all these artifacts (books do count as artifacts too after all) just lying around on the hillside, and second, why are the leaving my house?
Edit: On closer inspection I found even more artifacts near that fortress, a dwarf bone armor stand, a human-fitted dress, and a couple more books
Edit 2: I ended up hearing a rumor that the dress was wanted back in the fortress, though interestingly it was said to be last held by some rando. I wonder if that means it was stolen from the fort, but for some reason dropped right outside the fort, and dwarves aren't smart enough to grab it from 20 feet away.
Yeah, I have this same issue with a bunch of books I had in a cabinet that I built in a camp of mine. I haven't tried to reproduce it with other non-artifact items, although I do think I had a chest in the cabinet that stayed where it should be. I had in the camp a bunch of drunks in "wait here" mode, and I assumed they had been strewing them around during the hour I spent building a floor tile.
One book ended up a little buggy: it's in the cabinet and also in my backpack, and I can't pick up the one in the cabinet. Something like that.
Probably not related, but book handling is pretty shoddy in this version anyhow. Adventure mode bookcases don't work, and libraries in that world of mine have literally every floor tile four-deep with books and scrolls. Dwarf Fortress: Episode I: Knee-deep in the read.