When hitting a shulker bullet with a wind burst mace, it will not only launch the player, but do so at inconsistent heights. To reproduce, obtain a mace with the wind burst enchantment, spawn a bunch of shulkers, then avoid the projectiles until you stop levitating. When you hit the projectiles using the mace on the way down, they will often launch you up in an unpredictable manner.

Another way to reproduce the issue:

1. Place down an always active repeating command block with the following command: summon shulker_bullet ~ ~1 ~
2. Obtain a mace enchanted with Wind Burst
3. While falling down from >=1.5 blocks, hit the shulker bullets

Observed result:
The Wind Burst enchantment is triggered.

Expected result:
The Wind Burst enchantment is not triggered.