Drowned kill and pick up pufferfish without player interference, loading them permanently

Open a world in 1.21.7 in creative Mode, use the command “/summon drowned ~ ~1 ~ {CanPickUpLoot:1b}” to summon a drowned that can pick up loot and put it in water next to a pufferfish.

Expected result: The pufferfish puffs because of the presence of the drowned, which leads to the drowned getting damaged and killing the pufferfish, but not collecting the pufferfish-item, similar to how they cannot pick up glow ink sacs.

Actual result: The drowned kills the pufferfish and picks up the item, leading to it not beeing able to despawn, despite this beeing able to happen without any player interferance.

This could also happen to other mobs like zombies or husks.