Some shapes and "wmf" images appear with black background instead of transparent

Steps to reproduce:

1. Have LibreOffice 25.2.1 installed locally
2. Configure Office Server from xwiki.properties
3. Make sure Server state is Connected in Administration
4. Select the attached Office document 011-[FREE]-Clipart-4Pages-DOCX-1.docx
5. Click on Import
6. Access the page

Expected results: The images and shapes appear as per the imported document.

Actual results: One of the shapes and a "wmf" image appear with black background instead of transparent.

NOTE: On XWiki 15.10.12 the images are showing as per the imported document, with transparent background.

The issue is reproducing starting with 15.10.13 and on newer versions including 16.10.5