Feature-Class's attribute expressions does not work in Webscene

[AngelRomoSandoval]

Hello, 

I have the following Data:

When I click in the Feature Layer and I go to Visualization -> Pop-Ups -> Add Attribute expressions -> I create a new Attribute expressions and I insert it in a Pop-UP Window.

But when I add this Feature-Class to an Webscene (3D) the Attribute expression does not work in the Pop-Up, it appears empty. 

Pd: In a Webmap (2D) works properly.

Anybody knows why? is this a bug?