Didn't find any bugreport about this, sorry if there is one. 

Bug:

Changing the age of a villager with NBT data

data merge entity @e[villager,limit=1] {Age:-100}

this makes the villager turn around weirdly after every time the command is executed. 

Think they turn to east/south and it might be because it's looking at invisible villagers

don't know for sure. Don't really have time to test rn