character '0' not rendered in label

When I was adding some label to the map, a lot of character "0" are missing from the label. There is space where it should be "0". I don't know how to post a picture here, otherwise I would like to show you how it looks like.
I also paste the snippet that create the label.
/* featureId, objectId, height are parameters passed in the function */

featureId = viewer.entities.add({
     id: featureId,
     name: objectId,
     position : Cesium.Cartesian3.fromDegrees(
            lon, lat, height),
     billboard : {
          image : '..icon..',
          width : 20,
          height : 20
     label : {
          text : objectId,
          font : '14pt Arial',
          verticalOrigin : Cesium.VerticalOrigin.BOTTOM,
          pixelOffset : new Cesium.Cartesian2(0, -9)
     polyline : {
          positions : Cesium.Cartesian3.fromDegreesArrayHeights(
              [lon, lat, height, lon, lat, 0]),
          width : 2,
          material : Cesium.Color.WHITE

Are you using the latest version of Cesium?.

There is a bug in newer versions of Chrome that we worked around in Cesium. Since this is a Chrome bug, your only option is upgrade to the latest version of Cesium or file a bug report with Chrome and hope that they fix it.

If this is happening on the latest version of Cesium or with a different browser, please let us know.

I am using the latest version (Version 46.0.2490.86 m) of Chrome now.
Just replaced the old Cesium(1.11) with the new one (1.15) and this bug is fixed. Thanks.