Created attachment 138236 [details]
Example file made with Excel 2013, containing a Pie-Pie chart

If we create a simple Pie-Pie Chart in Microsoft Excel 2013/2016 the LibreOffice will not handle that, because there is no Pie-Pie chart between the diagram types. The Pie-Pie Chart will become a simple Pie chart in LibreOffice. 

Steps to reproduce:
1. Create a new spreadsheet in Excel 2013/2016.
2. Create a simple Pie-Pie Chart.
3. Save the spreadsheet in xlsx.
4. Open the file in LibreOffice Calc.

Actual results:
The chart type isn't a Pie-Pie anymore, but a simple Pie Chart.

Expected results:
There should be a Pie-Pie Chart between the diagram types.