Hi Matthew,
Thank you for contacting Syncfusion support.
We were unable to reproduce the reported issue “PDF Viewer is not working as expected”, we have shared the sample for same in the following location,
Please try the above sample and revert us with the modified sample and more details about your requirement. Also, can you please confirm us the platform in which you are using the PDF Viewer. It will be helpful for us to investigate more on your issue and assist you better.
Regards,
Akshaya