The bug
Fireworks for crossbow go through an entity if it is close to a player.
How to reproduce
/summon enderman ~ ~ ~ {NoAI:1b}
go up very close to it
Shoot an arrow using a crossbow
→ ✔ The arrow hitsShoot a fireworks rocket using a crossbow
[media]
→ ❌ The rocket passes right through the enderman.
Shulker fixed in 1.19.
Related issues
discovered while testing
relates to
Attachments
Comments

Can confirm in 20w51a.
Can confirm in 21w03a.
Can confirm in 21w05a.
Can confirm in 21w05b.
Can confirm in 21w06a.
Can confirm in 21w07a.
Video attached.
Can confirm in 21w14a.
Can confirm in 21w15a.
Can confirm in 1.17.
Fixed in 1.19.
[media][media]

A shulker hitbox is very different (entities can not walk through them), you sure this is fixed, and was not just not the case for shulkers?

That's what I thought. 🙂
@@unknown, Confirmed to affect 1.19.
It's weird, I've been using shulkers to test this report before and it's reproducible very well, since the shulker hitbox is solid enough.