Equipping armor or elytra from hotbar in Creative mode does not duplicate it

Summary:
When armor or elytra is equipped from the hotbar in Creative mode, it is not duplicated. When equipped on an armor stand, it is duplicated as expected.

Steps to Reproduce:

1. Obtain armor and elytra
2. Place the armor and elytra in the hotbar
3. In Creative mode, equip the armor and elytra from the hotbar

Observed Results:
The armor and elytra are not duplicated when equipped.

Expected Results:
Armor and elytra should be duplicated when equipped from the hotbar in Creative mode.

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Original Description:
When equipping amour from the hotbar it uses the Armour as it would in survival