I built shops in one of my worlds with villagers spawning in (I trapped them with fences). However, when I joined back my world, they escaped from the shops (the fences) since they got teleported to the center of a fence block, which is npot supposed to happen.

Steps to reproduce:
1. Trap a villager with fences
2. Leave your worl and join your world again

This doesn't always happen. It may happen if you re-join your world for a few more times.