NPrinting pdf doesn't render Powerpoint charts correctly (black instances)

Using Qlik Sense November 2017 and NPrinting November 2017 user can create a PowerPoint with charts without any issue. However if user will try to publish the same report as a PDF he may receive some chart objects covered from a black image.

This can occur by using QlikView as well.

Steps to reproduce:

1. Connect to the attached QVW and create a filter with no data
2. Create a PPT report and attach the filter
3. Import chart object and create a PowerPoint native pie chart
4. Preview the report (or run it by a task) in PDF format

The result should be a table (no data inside) but we get a black square instead as you can see in the attached PDF.

You get the correct result if you preview the same report in PPT format.