When a drowned throws a Trident, it doesn't copy the Trident item's NBT onto the trident entity's Trident
NBT tag. This means that enchantments from the trident aren't applied (impaling mostly)
Linked issues
Comments 3
Ah right, this is in some ways an extension as it should probably copy all NBT. Is this a duplicate?
For enchantments not working see MC-127321.