I changed the old modded save for the vanilla version. the issue might be seed-related.
the issue is on a vanilla server, and the only mods installed are client-side, but I will recreate the world in a completely vanilla setting.
it has not been an issue since the posting of this thread. I hope it doesn't happen again.
i don't have any footage from before the incident. and no, the villager was standing in the same spot where it cannot get out, and the trades had changed, even tho we already traded with it. it also happened that we found a good trade, and while we were getting the resources to trade with it to lock the trade, it changed without the workstation being removed and replaced.
I will give the exact details: it happened on an Aternos server, so limited ram, in a mountains biome.
step one: breed a villager from a breeder
step two: make it a librarian
step three: trade with the villager
step four: wait
I have no idea how I would specify it otherwise, I'm not even sure it is a bug, it just happened and no player was involved.
ps. another librarian also randomly disappeared along with its workstation
i have noticed an absence of activity on this post. is there anything I can provide to further advance this issue?