If you want to pick a block from the search bar creative menu using Hotbar slot keybind, then the search bar is replaced by the keybind, instead of placing 1 stack of that block into the Hotbar slot.

My kebind is :
Slot 1 = 1

Slot 2 = 2

Slot 3 = 3

Slot 4 = 4

Slot 5 = q

Slot 6 = r

Slot 7 = v

Slot 8 = c

Slot 9 = x

All the drop, load toolbar and save toolbar has remapped with another key

How to reproduce :

1. Changes the Hotbar slot 4 into a letter q (for example)
2. Go to search (compass)
3. Search dirt (for example)

3. Hover the dirt

4. Press q

(Then the search bar become "dirtq", instead of putting the dirt to slot 5)