For Minecraft 1.21 in a datapack if you make an enchantment with the effect component "minecraft:projectile_spawned" and the result being "run_function", the function will only run when the crossbow (because that's what the enchantment is set to be used for) fires and arrow. But the bug is that the function won't run when the crossbow shot a firework
Mecha_Andrew
I'm running into this bug too.
For Minecraft 1.21 in a datapack if you make an enchantment with the effect component "minecraft:projectile_spawned" and the result being "run_function", the function will only run when the crossbow (because that's what the enchantment is set to be used for) fires and arrow. But the bug is that the function won't run when the crossbow shot a firework