Allay can't use off-hand correctly

Allay can't use off-hand correctly.

Reproduce using the following command:

/summon minecraft:allay ~ ~ ~ {HandItems:[{},{id:grass_block,Count:1b}]}

/summon minecraft:allay ~ ~ ~ {HandItems:[{id:grass_block,Count:1b},{id:grass_block,Count:1b}]}

This results in:

1. Item floats in front of the allays.
   
2. Strange holding position when the allay holds the item in both hands.
   
3. You can't remove items from the alays off-hand.