Take a wooden sword and enchant it with sharpness 5.
Spawn a creeper and get its health with the following command:

/data get entity @n[type=minecraft:creeper] Health

It has 20 HP.

Hit the creeper with your sword and get its health again.
It has lost 7 HP: 4 from the sword and 3 from the sharpness.

Hit the creeper with a critical hit and get its health again.
It should have lost 10.5 HP: 7 as before and 50% more from the critical hit.
Instead, it has lost only 9 HP: 4 from the sword, 3 from the sharpness, and 50% of the sword's base damage from the critical hit.

The same issue happens for other values, other enchantments, other tools and on other mobs.
A smite 100 netherite axe deals (10+2.5×100)×(1-0.8/25)=251.68 damage to a wither without critical hit and should deal 251.68×1.5=377.52 damage with the critical hit, but instead deals only 251.68+10/2=256.68 damage.
A tool with a custom enchantment made to deal 0 damage indeed deals 0 damage without critical hit, should also deal 0 damage with the critical hit, but instead deals half the tool's base damage.