[MC-305378] Skeletons no longer charge their bows if their CustomName is continuously changed

Skeletons interrupt the loading of their bows when their CustomName is changed using the /data command.

I noticed this behavior after programming a datapack where a mob's current health is displayed as hearts in the CustomName. To make this possible, the CustomName is set every tick. As a result, skeletons will follow a player but won't attack them with their bows.

I also reproduced this with a simple setup (see the YouTube video or the Video attached). I used the command execute as @e[type=minecraft:skeleton] run data merge entity @s {CustomNameVisible:1b,CustomName:"indic-1"} (with indic-2) to repeatedly switch the CustomName of skeletons back and forth. It can be observed that the skeletons interrupt the loading of their bows every time the CustomName is changed. I then activated a repeating command block that permanently (every tick) changes the skeletons' custom names using the command execute as @e[type=minecraft:skeleton] run data modify entity @s CustomName set from entity @s Health. This results in the same behavior I observed with the data pack.

This behavior affects not only skeletons, but also Strays and Parched.

YouTube Link: https://youtu.be/3qp_bWV6R6I or Video attached.

Environment

Java Edition
Minecraft Launcher
Version: 1.21.11

Linked issues

relates to 2

MC-274426 Continuously altering the data of a mob makes that mob unable to turn its head left and right and will make the lead unbreakable if that mob was leashed Open

MC-305283 Skeletons no longer charge their bows while their data is continuously changed Open

Attachments

World.zip

Comments 6

marbrueck 2026-01-01T04:14:41Z

Here is an excerpt from my datapack code, which adjusts the CustomName every tick, based on their health.

execute if score @s mh.mobhealth matches 1 run data merge entity @s {CustomName:[{"atlas":"minecraft:gui","sprite":"hud/heart/half"}]}
execute if score @s mh.mobhealth matches 2 run data merge entity @s {CustomName:[{"atlas":"minecraft:gui","sprite":"hud/heart/full"}]}
execute if score @s mh.mobhealth matches 3 run data merge entity @s {CustomName:[{"atlas":"minecraft:gui","sprite":"hud/heart/full"},{"atlas":"minecraft:gui","sprite":"hud/heart/half"}]}

[MOD] Greymagic27 2026-01-01T12:16:35Z

Please attach the world/strucure file and datapack so this can be more easily reproduced

marbrueck 2026-01-01T19:41:45Z

This is the world in which I reproduced the behavior. The data pack is also present and just needs to be activated.

[media]

AnonAya09081227 2026-01-10T16:31:45Z

It is related to

MC-305283

marbrueck 2026-04-18T13:06:19Z

This also applies to Breezes, which neither jump away nor attack the player. Tested in recent Version.

marbrueck 2026-04-18T13:15:09Z

Wardens also behave strangely if their custom name is permanently changed. For example, they no longer attack players properly, and they also seem unable to correctly identify the source of sounds.