Wearing a piece of armor in creative mode sometimes does not create a duplicate

If you try and right-click while holding a piece of armor, it now uses the held armor piece instead of duplicating it. I happened to me randomly, but I tried to do it again and it duplicated it correctly

To reproduce

1. Have a piece of armor in your hotbar
2. Hold the armor and right-click
   → It actually uses the armor piece instead of duplicating it.