Viewer API issue with specific models

I was testing some models in a project of mine, and get this result, I think this is related to some setting, also because the model can be seen correctly in your main site.

The model in question is this one :
And this was the result:

Can someone give me some hints?

Do you reproduce consistently ?
looks like a video card problems, often just closing chrome and/or rebooting fixes those

Unfortunately yes I also tried a different machine but the problem persists…
but i never have issue if I try to visualize it in your site.

could you provide a reproducable steps, a jsfiddle or codepen or a link to the code ?

First sorry for the long time it take me.
I was performing some tests, and as I was expecting the problem arise also in the most basic of the scenes.
I created a codepen from the example code provided form you guys, but the problem is still present, I configured the render with the same parameter I use in the project.

I couldn’t reproduce here on two different computer.
could you post a screenshot of on the computer that fails ?