White backgrounds not displaying (they appear transparent)

Hello All!

I'm having a bit of a weird error with my Adobe Acrobat. 

Anytime I try to open a PDF with a white background, the white doesn't display, instead it is transparent. 

I can tell the documents are meant to have a white background because they have such in the online previews, and include such things as government forms. 

I have been manually adding a white background in Acrobat to make the documents readable (they're quite hard to read with the transparent background) but this is not ideal - esp when some PDFs are locked and I cant modify them.  

Has anyone run across this issue before? Any help greaty appreciated!