Thanks for reaching out. I would suggest you to please check the known limitation while using 3D tranform feature: Adobe XD User Guide As per the limitation the 3D transforms are not yet available in the SVG export/import workflows.
If you would like to upvote or submit a feature request related to this feature, use this link It will help the team prioritize current features and limitations.
But my concern is to export it in pdf format.
I am sorry for the delay in response. Could you please share the XD file with me so that I can investigate at my end? You may upload the file to a shared location such as Creative Cloud or Dropbox and share the URL with me.
I will try my best to investigate.