How to reproduce:
1. Give yourself a single item.
2. Try to put it in an inventory/container slot while swinging cursor above the slots.
Happens in creative, survival inventory and any GUI container.
Linked issues
duplicates 1
Comments 7
Does MC-109566 describe your issue?
Just reproduced the bug more accurately, yeah, looks like MC-109566 describes it better. While reproducing I found another bug: in creative inventory you can't stack same scattered items by double-clicking one of them, but it works fine in survival.
This another bug is MC-65086
And no. Don't blame my mouse. It works perfectly. Pressing force doesn't change the situation.