GLTF mesh BLEND mode is opaque on one side

I am seeing that double-sided transparent meshes using the BLEND alpha mode are opaque on one side. It should look like this:

Instead when I open it in the Chronos sample viewer it looks like this:

Is this a bug in Cesium? I am attaching the sample gltf file. You can drag it into the sample viewer.
test_blend.gltf (9.4 KB)

Hi @chadj2,

glTF-Sample-Viewer doesn’t use CesiumJS to render glTFs. Their code is in this repository, so I would suggest opening an issue there for your model.

CesiumJS seems to render this model correctly though:

I appreciate the assistance. It seems there is nothing wrong on my end and the problem is with the sample viewer.