Since the new raiding changes in the last snapshot, 19w13a and b, it also changed the Villager AI a little bit.
This bug somehow made it's return once again! (Because I know it was fixed not that long ago)

Simply, ravagers attack villagers as normal, but the villagers don't run away from them again. They do run though when they get attacked.

This also affects pillagers, vindicators, evokers, zombies and husks.

Note: I tested this again in the (b) snapshot, and sometimes villager will run away from vindicators, but not that often.