WASM: Images with layer effects and gradients are not rendered correctly

import QtQuick 2.11
import QtQuick.Window 2.11
import QtGraphicalEffects 1.0

Window {
    visible: true
    width: 640
    height: 480
    color: "grey"

    Rectangle {
        id: mask
        width: 100
        height: 100
        radius: 50
        anchors.centerIn: parent
    }

    Image {
        anchors.fill: mask
        fillMode: Image.TileHorizontally
        source: "gradient.png"
        layer.enabled: true
        layer.effect: OpacityMask {
            maskSource: mask
        }
    } 

    /**
     Same optical problem with the linear gradient

    LinearGradient {
        anchors.fill: mask
        start: Qt.point(0, 0)
        end: Qt.point(0, mask.height)
        source: mask
        width: mask.width
        height: mask.height
        gradient: Gradient {
            GradientStop { position: 0.0; color: "#F60000" }
            GradientStop { position: 1.0; color: "#F6F600" }
        }
    }
    */
}