BUG: The DeSelect in the Gesture Box does not work

Hi, starting out in 2.8

I’m trying to customize my selection box so that dragging and releasing right click “selects”, which works. And also that when I press left click, it deselects what’s in the selection box, which ALMOST works.

However, the DeSelect part of the gesture box is non-functional. It selects instead. No key or mouse button, when placed in the DeSelect slot, makes it deselect.

Based on my experience of 2.79, it should all function. So is this a bug? Is there a special way to make deselect work?

Note: I do not want to use modifier keys. I can already make something like alt-right click drag to deselect.

Thanks!

I’ve added an image of the shortcuts I had in 2.79, where the Deselect was used indentically, and where it functioned.