To reproduce:
1. Procure multiple arrows and an unenchanted bow.
2. /summon minecraft:zombie ~ ~ ~ {CanPickUpLoot:true}
3. Shoot arrows at ground.
The zombie will not pick these up even if they have empty hands.
Linked issues
relates to 2
testing discovered 1
Attachments
Comments 13

From wiki:
CanPickUpLoot: 1 or 0 (true/false) - true if the mob can pick up loot (wear armor it picks up, use weapons it picks up).
How is this a bug? The arrow is an entity, not an item. I am pretty sure there was never a version in Minecraft where this happened, so this is more of a feature request.
Arrows shot by non-skeleton, non-Infinity means can be picked up by players, so the fact that other mobs can't pick them up under the same conditions very much is an issue.
Relates to MC-270193
Relates to MC-270193