Villagers sometimes don't immediately run to houses when raids begin

The Bug:

Villagers sometimes don't immediately run to houses when raids begin.

Steps to Reproduce:

1. Locate and enter a village.
2. Give yourself the bad omen effect in order to start a raid.
3. Watch the villagers closely as the raid is about to begin.
4. Take note as to whether or not villagers sometimes don't immediately run to houses when raids begin.

Observed Behavior:

Villagers sometimes don't immediately run to houses.

Expected Behavior:

Villagers would immediately seek shelter.