Trying to equip an item to an armor stand causes the item to become stuck in the inventory

Steps to Reproduce:

1. Place down an armor stand
2. Press the use button on the armor stand while holding an item
3. Press the use button on the armor stand again while holding the same item
4. Open your inventory and try to move or drop the item

Observed Results:
The item is stuck in the player's inventory.

Expected Results:
The item should be able to be moved and dropped from the inventory.

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Original Description:
When I tried to equip an elytra to an armor stand in the 1.16 beta it completely broke the elytra as an Item. When I dropped it on the ground it was back to normal. (I also wasn't able to equip the elytra to the armor stand in the first place)