Shulkers sometimes get stuck in their opened or closed states after being aggressive towards an entity

The Bug:

Shulkers sometimes get stuck in their opened or closed states after being aggressive towards an entity.

Steps to Reproduce:

1. Build the setup as shown in the provided attachment. setup.png
2. Using spawn eggs, spawn shulkers on top of every diamond block within the setup.
3. Stand on top of the gold block and spawn an iron golem with a low amount of health by using the command provided below.

   /summon minecraft:iron_golem ~ ~ ~ {Health:1f}

4. Wait for the iron golem to be killed by the shulkers.
5. Observe the behavior of all the shulkers for around thirty seconds.
6. Take note as to whether or not most shulkers sometimes get stuck in their opened or closed states after being aggressive towards an entity.

Observed Behavior:

Shulkers sometimes get stuck in their opened or closed states after being aggressive towards an entity.

Expected Behavior:

Shulkers would not get stuck in their opened or closed states and would naturally peek as normal.