Relates to MC-279556.

When you attack a neutral mob, it's supposed to fight back. However, under certain, strange, cases, they won't. It seems to happen whenever a command with a target selector containing nbt={any-nbt-data-here} is run on the same tick as a neutral mob being attacked.

Steps to reproduce:

1. Place a repeating command block and add any command that contains a target selector with the 'nbt=' field in it, and power it.
2. Spawn any neutral mob.
3. Make sure you aren't in peaceful difficulty.
4. In survival, attack the neutral mob.
5. Observe that it doesn't attack back.
6. Unpower the command block
7. Attack the mob again.
8. Observe that it attacks you back as intended again.

Notes:

• If you attack a neutral mob that will cause other mobs of the same species to attack you as well, while having a method to produce the bug active, the other nearby mobs of the same species do attack you (although they don't change to their attacking pose and/or texture), but the attacked mob doesn't attack.
• Other methods of angering neutral mobs without attacking them, such as looking an enderman in the eyes or going near a spider in a dark area, still work as intended.

Video: 2025-01-15 18-15-40.mkv You'll need to download it because onedrive won't play mkv videos for some reason

Found this bug while using datapacks, as functions can also produce the bug.

Bug started in 25w02a.