Inner shadow for background rectangle not work properly

Trying to make inner shadow for background rectangle of quick control. For example for background of Pane in BusyIndicatorPage of Qt Quick Controls 2 gallery example like this:

    background: Rectangle {
        color: "white"
        layer.enabled: true
        layer.effect: InnerShadow {
            cached : true
            color: "black"
            samples: 32
            radius: 16
            spread: 0.5
        }
    }

There is no shadow at all:

Here http://stackoverflow.com/questions/27484767/inner-shadow-on-qml-rectangle found a workaround related to QTBUG-27213 to set source of InnerShadow to the item above the item I'm trying cast a shadow within.

This workaround works for usual rectangle on the page, but not works for background rectangle (more precisely item with rectangle).

InnerShadow stars works (in both cases: in code above or in workaround) when there is offset. On the pic there is a result when 1px horizontal offset is set, there still no shadow on top and bottom edges (until vertical offset).