A desync occurs when dropping your held item and swapping to another inventory slot at the same time.
Steps to reproduce:
Populate at least two hotbar slots with items, I recommend the one you're switching to being one near your drop button.
While holding an item in your hand (selected in the hotbar), hit the drop button AND the button to switch to another hotbar slot at the same time. (i.e. 'Q' + '1').
If done correctly, which seems relatively common, the item in your switched-to hotbar slot disappears, while the item you switched from drops as expected.
The item in your switched-to slot will reappear if you open your inventory and click it, as with most ghost blocks/items.
Interestingly, if your ghosted item is a pickaxe, you can mine stone at normal punching speed, but still get the drop as if you used the pickaxe. This DOES consume durability as expected.
Linked issues
is duplicated by 32
MC-147213
If press q and 1-9 in same time 1 of 2 items is missing
Resolved
MC-159665
disappearing items
Resolved
MC-161600
if you press the drop key and a number the selected item will disappear
Resolved
MC-162937
Item Drop Deletion
Resolved
MC-173712
Item disappearing from the enventory
Resolved
Attachments
Comments 14
Happens to me on servers ever since 1.8. It seems to create some sort of phantom item in the slot but when you go into your inventory and click the spot, the item suddenly reappears
I can confirm for 23w05a. Edit: I also found this works in 1.19.3 and I found the bug accidentally before seeing this report.
Confirmed bug. Just unintentionally experienced it.
1.14.3