Creating a custom visual with a specified icon not working

I am using DevTools to create a visual and specifying the icon in the visual settings.

The generated pbiviz > css file has 2 icon defenitions:

.visual-icon.MyComponent1466514674636{ background-image: url(data:image/png;base64,iVBORw...=);}

.visual-icon.MyComponent1466514674636{ background-image: url(data:image/png;base64,iVBORw0KG...==);}

The first one being the default "spanner" icon, the second one being the correct one.

However, in PBI (web) it shows the wrong spanner icon.