Ghost Block Number Fast-hotbaring

Sometimes, while choosing a block from the creative menu using "1" to "9" buttons you stack of blocks can be like this (FILE 3.1)

How I accomplished it (I have done these actions in a very short amount of time):

1. Hovered my cursor over the block I wanted to get. (Example: Oak Planks)
2. Pressed the "1" to "9" button on the keyboard. (Example: "1")
3. Repeated with all 6 wood planks types.
4. "Enjoyed" the ghost block bug.

P. S. I wasn't able to recreate the bug another time.
P. S. S. Sorry for video lags.