Gravity PDF officially supports Adobe Acrobat Reader and Adobe Acrobat PDF viewers – Adobe is the company who originally developed the PDF specification. This means if a PDF generated with Gravity PDF has display issues in the PDF reader you are using, but shows correctly in Adobe Reader/Acrobat, we won't consider it a bug with Gravity PDF.
These days browsers ship with their own PDF viewing software so that you don't need to install a third-party plugin. This is great in theory as it makes PDF documents more accessible to everyone, but in practice it can cause display problems. Why? Because building software that correctly interprets the PDF specification is challenging. Just take a quick look at the latest PDF specification and tell us it wouldn't give you a headache.
If you notice your generated PDF displays incorrectly in your browser's viewer, the best option is to save any PDF documents to your computer and open them with Adobe Reader.