Duplication glitch (almost)

I almost found a dupe glitch, but it turns out not to work.

In Creative mode, you can duplicate items using the Pick Block key. However, I found that in Survival mode you can actually create a "sort of" dupe in a similar manner. If you use middle click to fill a slot with an item in survival mode, it looks like you can still dupe items this way, but as soon as you release middle click, the items disappear. I thought I could exploit this with a dropper, but it's only a client side bug, so I can't actually dupe anything.

How to reproduce

1. Enter a Survival mode world
2. Equip any item
3. In survival mode, hold that item in the cursor in a chest GUI and try to middle click drag in the chest, same as in Creative mode
4. You can see the item being duped, but as soon as you release click, everything goes away.

I was honestly a little disappointed when I realized this wasn't an actual duplication glitch, but I want you to fix this, not because it's a real problem, but because it looks a little unprofessional.

Thank you for taking the time to read this.