Hosted Asset as Background-Image not working

Hi there

I’m building a landing page and I need to use a hosted asset as Background-Image. I can’t use local assets because of the hosting. My problem:

I import an image as hosted asset. Then I drag the image from the Asset Manager to the Class Editor’s Background-Image field. In the Class Editor it looks fine, but in the page there is no Background-Image. When I export the Page, the URL String in the CSS Style Property is empty:

background-image:url("");

Is this a bug? Or how can I use hosted assets in styles?

Thanks for any help,
Florian