The hitbox to trigger the movement of the slider in the creative inventory includes 2 pixels to the right of what the actual slider texture indicates but none to the left.
MC-266899
Hitbox of scroll slider in Creative inventory is too large on one side
Open
4
(Unassigned)
Confirmed
Platform
Low
UI
1.20.2, 1.20.3 Release Candidate 1, 1.20.4 Release Candidate 1
Retrieved
Confirmed in 1.20.3 pre 1