QSurfaceDataProxy not working in QML

[sauropodbob]

Hi

I am trying to use QSurfaceDataProxy from python in QML but I keep getting this error "Unable to assign [undefined] to QSurfaceDataProxy*".

Can you help with what could be the cause? Thank you

Here are the code snippets

python snippet

class Surface2(QObject):
    name_changed = Signal(QSurfaceDataProxy)
    simulator_nameChanged = Signal(str)


    def __init__(self, parent=None):
        QObject.__init__(self, parent)
        
        self.surfaceproxy = QSurfaceDataProxy()
        # self.surfaceseries = QSurface3DSeries(self.surfaceproxy)
        self.create_data()
        self.test_name = "blue"

    @Property(str, notify=simulator_nameChanged)
    def color_name(self):
        return self.test_name

    def create_data(self):
        x = [1,2,3]
        y = [3,4,5]
        z = [6,7,8]

        data_arr = []
        for i, item in enumerate(x):
            row = [QSurfaceDataItem(QVector3D(x[i], y[i], z[i]))]
            print(row[0].x())
            data_arr.append(row)
        self.surfaceproxy.resetArray(data_arr)
        print(self.surfaceproxy.rowCount())
        return self.surfaceproxy

    @Property(QSurfaceDataProxy, notify=name_changed)
    def output(self):
        return self.surfaceproxy

qml snippet

        Surface3D {
            id: surfacePlot
            width: parent.width
            height: parent.height
            theme: Theme3D {
                    type: Theme3D.ThemeStoneMoss
                    font.family: "STCaiyun"
                    backgroundColor: surfaceDataModel.color_name
                    font.pointSize: 35
                    colorStyle: Theme3D.ColorStyleRangeGradient


            Surface3DSeries {
                itemLabelFormat: "Pop density at (@xLabel N, @zLabel E): @yLabel"
                dataProxy: surfaceDataModel.output

            }
        }