Layerlist widget with only one layer can be expanded

HelenZhou

Hello,

I have a customized widget which load several layers:

            array.forEach(this.config.layers, function (layer) {
                        this.addLayerToMap(layer);
                }, this);

When I open the LayerList widget (the build-in widget from web appbuilder 2.8 - Layer List widget—Web AppBuilder for ArcGIS | ArcGIS ), only one layer can be expanded. With the same code, if the "layers" array only has one layer, this layer is expandable in the LayerList widget. Does anybody else has the same issue? Can LayerList be customized to work when multiple layers added at a time?

Thanks so much

Helen