Fall damage will sometimes not apply to the player after a fall if they just previously managed to land a successful smash attack with a mace. While it is not required for reproducing the behavior, this issue is exacerbated with jump boost, where the player can more easily take fall damage after landing a smash attack.

Steps to Reproduce:

1. Summon an entity with NoAI (in this case, iron golem)

   /summon minecraft:iron_golem ~ ~ ~ {NoAI:1b}
   

2. Get high enough off the ground to perform a smash attack
3. Smash attack the iron golem
4. Quickly teleport the player high enough into the air to take damage:

   /tp @p ~ ~6 ~
   

Observed vs. Expected:

The player will (very often) not take fall damage during the second fall where they do not perform a smash attack, as the fall damage prevention seems to last long enough past the player landing on the ground.

It would be expected that after the player performs the smash attack, any form of fall damage would apply thereafter.

Videos:

Expected:
expected_fall_damage.mp4
Observed:
observed_fall_damage.mp4
(note; notice how this bug is inconsistent, and does not always apply)
With jump boost:
observed_fall_damage_leaping.mp4

Using a high level of jump boost:
https://drive.google.com/file/d/1iTZbj25HmPHq3_5KE9ZqPoIY4sth_GTb/view?usp=drive_link
(note; per MC-10755 effect levels past their default allowed values are not supported. However in this case, it is helpful to demonstrate the bug)