wasm: DropShadow breaks mouse input

import QtQuick 2.12
import QtQuick.Window 2.12
import QtGraphicalEffects 1.0

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")    
    Text {
        anchors.centerIn: parent
        text: "Hello, WASM!"
    }
    Rectangle {
        id: rectangle
        width: 100
        height: 100
        color: "red"
        visible: false
        enabled: true
    }
    MouseArea {
        anchors.fill: rectangle
        drag.target: rectangle
    }
    DropShadow {
        anchors.fill: rectangle
        source: rectangle
        verticalOffset: 4
        horizontalOffset: 4
        radius: 10
    }
}