Access attachment field not saving changes to pdf (1 Viewer)

I am using the attachment field in a table. I attach a PDF to a record. I then open the PDF and "mark it up" using the marker tool. I close the PDF and it asks me to save it. I respond by clicking Yes. It takes me back to the Attachment dialogue box. I re-open the PDF and the changes are not there. However, if I go to MyDocuments folder, the updated pdf is saved there. Why won't it update the attached PDF?