Mobs without common drops don't drop anything with datapack loot table

Mobs who don't drops items (Vex, Piglin, Piglin Brute...) doesn't drop anything if you add a loot table for them.

Example for Piglins, I wanted them to drop emerald for an adventure map, but even after creating the loot table, they still don't drop anything. However, it works with other mobs.

A json file in include as en example.