Mace smash attack damage does not work with mobs, even though particles and sounds happen

Mobs holding the mace will not deal extra damage when falling down on their target, even though you can see and hear the smash attack happen.

Steps to reproduce:

1. Build a 5 block tall pillar

2. Summon a husk on top of it:

   /summon husk ~ ~ ~ {CanPickUpLoot:true}

3. Give the husk a mace

4. Stand at the base of the pillar in Survival mode and allow the husk to fall on you

Observed result:
The husk falls on you, performing a smash attack with particles and a sound effect, however you take normal damage from the attack.

Expected result:
You would take extra damage from the attack (enough to one-shot an unarmored player).