Using /replaceitem entity on slots(armor.head, armor.chest, armor.legs and armor.feet) were invisible

How to Reproduce
1. Go to chat
2. Type /replaceitem entity @p (slot.armor.head, slot.armor.chest, slot.armor.legs and slot.armor.feet) (0 or 1) (items you want to replace entity)
3. Hit enter

Observed Results
The item is invisible.

Expected Results
The item should be visible.