Mobs spawned from spawners or /summon never drop their equipment

[robertosu]

Expected behavior

A mob with equipment, say a skeleton should always drop its bow when killed with a looting 255 sword, whether spawned by commands, spawners or egg.

Observed/Actual behavior

Only natural and egg-spawned mobs drops its equipment, /summon and from mob spawner (natural generated spawner) don't

Steps/models to reproduce

Get a Diamond Sword with max Looting and Sharpness

Hunt natural skeletons - they always drop bow
Spawn skeletons with eggs - they always drop bow
Find a skeleton spawner - spawned skeletons never drop bow
Use /summon minecraft:skeleton - these never drop bow either

Plugin and Datapack List

Tested in a fresh server folder.

Paper version

This server is running Paper version 1.21.4-75-main@9f90b4c (2025-01-04T21:02:23Z) (Implementing API version 1.21.4-R0.1-SNAPSHOT)

Other

No response

[Warriorrrr]

This is a vanilla issue that's been marked as fixed in the next update: https://bugs.mojang.com/browse/MC-278683