I am using a Baffin (RX-460 4gb) to render. I followed the Blender Guru Earth tutorial. It utilizes cycles. It basically creates an earth using 3 layers (Earth, Clouds, Atmosphere).
When I CPU render the object, it accurately renders the composite of the three layers. When I GPU render it only shows the "top" layer- e.g. atmosphere. A GPU render of each layer is accurate, but it will not produce a composite of all the layers properly.
You can see the correct CPU output versus the incorrect GPU output .