Instead of destroying after creating the viewer, set false calling the constructor:
window.viewer = new Cesium.Viewer('cesiumContainer', { baseLayer: Cesium.ImageryLayer.fromProviderAsync( Cesium.TileMapServiceImageryProvider.fromUrl( Cesium.buildModuleUrl("Assets/Textures/NaturalEarthII"), ), ), animation: false, timeline: false, geocoder: false, skyBox: false, skyatmosphere: false, sun: false, moon: false, });