Copy and Paste a Graphic/Decal in Dimension Material no longer working

I've been using Dimension for a while to create Can Mockups of illustrated Beer Labels.
In previous versions of Dimension (before 4.0) I've been able to copy and paste a decal in the Material Properties.

I could stack various layers of beer labels with different areas of transparency to achieve the metallic and gloss effects on the packaging label.

Copying and pasting meant each layer was in exactly the same position. I would click on the decal in the material panel and press ctrl C to copy and ctrl V to paste., then I could relink to the new layer image keeping the all of positioning information.

Now this no longer works, I have to manually add a new layer and rescale and adjust each layer's position by hand to try and get the layer to stack accurately (which is impossible) - the layers are always a pixel or so out.

Is this a bug or has this functionally been removed Please?