"grey" background for clicked slots stays with the first even if you move your mouse around

[Wunka]

Steps to Reproduce and Observed Behavior

2026-01-25.21-07-08.mp4

Shift-Click on a slot and then move your mouse around without releasing both left-click and shift.
The slot where you started clicking will have this "grey" background and even if you move your mouse around this background will stay with this slot.