Slime balls sneezed by pandas cannot be picked up

The bug

Slime balls sneezed by baby pandas can't be picked up by the player or hoppers.

How to reproduce

1. Run

   /fill ~-10 ~-1 ~10 ~10 ~-3 ~-10 air
   /fill ~-10 ~-1 ~10 ~10 ~-1 ~-10 hopper
   /setblock ~ ~3 ~ minecraft:repeating_command_block
   

   Put the following command into the command block

   /summon minecraft:panda ~ ~-1.8 ~ {HiddenGene: "weak", HandDropChances: [2.0f, 0.085f], PersistenceRequired: 0b, MainGene: "weak", Age: -56779}
   

2. Active the command block, stop it when there are 300 baby pandas.
3. Wait, till a baby panda sneezes a slime ball.
   → You and the hoppers can't pickup the slime ball(s)