Polygon hierarchy attribute CallbackProperty bug

[cnchore]

What happened?

After CallbackProperty is used in the hierarchy value of polygon, two polygons will be rendered if the hightreference attribute value of Polygon is modified again.

`
const viewer = new Cesium.Viewer("cesiumContainer");

const redPolygon = viewer.entities.add({
name: "Red polygon on surface",
polygon: {
hierarchy: new Cesium.CallbackProperty(() => {
const hierarchy = new Cesium.PolygonHierarchy();
hierarchy.positions = [
Cesium.Cartesian3.fromDegrees(-115.0, 37.0, 50000),
Cesium.Cartesian3.fromDegrees(-115.0, 32.0, 50000),
Cesium.Cartesian3.fromDegrees(-107.0, 33.0, 50000),
Cesium.Cartesian3.fromDegrees(-102.0, 31.0, 50000),
Cesium.Cartesian3.fromDegrees(-102.0, 35.0, 50000),
];
hierarchy.holes = [];
return hierarchy;
}, false),
heightReference: Cesium.HeightReference.NONE,
perPositionHeight:true,
material: Cesium.Color.RED,
},
});

setTimeout(()=>{
redPolygon.polygon.material=Cesium.Color.BLUE;
redPolygon.polygon.heightReference=Cesium.HeightReference.CLAMP_TO_GROUND;
redPolygon.polygon.perPositionHeight=false;
},3000);

viewer.zoomTo(viewer.entities);
`

Reproduction steps

Sandcastle example

No response

Environment

Browser:
CesiumJS Version:
Operating System:

[Fav]

hierarchy: new Cesium.CallbackProperty(() => {
......
}, true),

[ggetz]

Thanks for the report @cnchore!

The workaround @Fav suggests seems to work. But I don't think it makes sense that this is required for the behavior to work as expected. So I'll leave this issue open.