I am unable to flip-horizontal all elements in the PDF.
Flips the objects but not the text.
Craig - is your question about using Adobe XD to export a PDF file? Or are you using Adobe Acrobat to create/edit a PDF file directly? If you're using XD, could you post screenshots of what your design looks like in XD compared to the exported PDF?
I created the PDF via InDesign CC2015 and trying to F-H with Acrobat CC2015.