Label Display Problem after Opening Clustering

CesiumJS
1

1. A concise explanation of the problem you're experiencing.

When the cluster is opened, the point label that is not within the scope of the cluster fails

Like this：
before ：[图片]
after ：[图片]

2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.

var viewer = new Cesium.Viewer('cesiumContainer');

var options = {
    camera : viewer.scene.camera,
    canvas : viewer.scene.canvas
};
var dataSourcePromise = viewer.dataSources.add(Cesium.KmlDataSource.load('../../../../Apps/SampleData/kml/facilities/facilities.kml', options));
dataSourcePromise.then(function(dataSource) {
    var pixelRange = 15;
    var minimumClusterSize = 3;
    var enabled = true;

    dataSource.clustering.enabled = enabled;
    dataSource.clustering.pixelRange = pixelRange;
    dataSource.clustering.minimumClusterSize = minimumClusterSize;

    var viewModel = {
        pixelRange: pixelRange,
        minimumClusterSize: minimumClusterSize
    };
    Cesium.knockout.track(viewModel);

    var toolbar = document.getElementById('toolbar');
    Cesium.knockout.applyBindings(viewModel, toolbar);

    function subscribeParameter(name) {
        Cesium.knockout.getObservable(viewModel, name).subscribe(
            function(newValue) {
                dataSource.clustering[name] = newValue;
            }
        );
    }

    subscribeParameter('pixelRange');
    subscribeParameter('minimumClusterSize');

    Sandcastle.addToggleButton('Enabled', true, function(checked) {
        dataSource.clustering.enabled = checked;
    });

});

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

After opening the cluster, I want all points to show label

4. The Cesium version you're using, your operating system and browser.
Cesium 1.55 / chrome
                                                                 Thank You , Liu

2

The screenshots are attached.

![1`T~WL4L[H1P9$SZK)29]0.png|553x291

![05]BL9L6OY){R6$SV29H)8.png|338x300

3

I think this is a known issue. See the discussion here, as well as a possible fix:

https://github.com/AnalyticalGraphicsInc/cesium/issues/6087