This bug is not just effecting villagers, but other mobs aswell. Prime example of the broken AI/pathfinding is that villagers try to go to the building and try jumping on a block that has a half slab on it. They also sometimes get stuck when they're passing next to Vertical trapped doors, and they also try to jump across fences. As seen from the pictures bellow, one of them shows that two villagers can get stuck in water and do not try to get out of it, There's a half slab on the block that they can get out from but they dont even jump on the water like they used to.
EDIT: The leatherworker shown in the picture bellow tries to get to the building thats on the other side of the farm and there's a path that leads around it. When he desides to go around it, he goes back and tries jumping over the fence again (The path that leads around the farm is one block wide and by it there's trapdoors placed on the sides of some leaves, when he tries to go to this path he jumps where the trapdoors are (thinking they're a full block) and then he spins around for a bit and goes back to the fence).
Please fix this issue!