Villagers walk back and forth instead of standing next to some point of interest. You can see it, when villager goes to his job point and quickly walks back and forth near it.
I think it happens because when villager randomly walks around he can go abroad area of point of interest, and when it happens he quickly comes back.
Solution:
Villager randomly walks around only in the area of the point of interest.
Not fixed in 19w12a:
though villagers have stopped to do it quickly, they still walk back and forth