DropArea signals seem wonky. Entered, exited, dropped aren't when I expect.

[Yosemite]

The Entered, exited, and dropped signals aren't being emitted when I would expect them to be. I've created a DropZone thusly:

import QtQuick 2.7

DropArea {
    id: dropArea

    height: 120; width: 120

    onEntered: console.log("enter")
    onExited: console.log("exit")
    onDropped: console.log("drop")

    Rectangle {
        id: rect
        anchors.fill: parent
        color: "grey"
        border.color: "black"
        border.width: 4

    }

}

When I drag an item over this I get no signal. When I drop it the first time I get no signal. However - if I move it around within the DropZone (without dragging it out) i will get both signals.

Subsequently, when I drag the item out and drop it somewhere else the DropZone emits entered and Dropped again one last time. I never get Exited.

Is this the expected behavior?