I have a special swirl on top of most of the pages in a 405 page book. Some of the swirls are not centered equally from the text above and below them. When I try to move it, the swirl stays in place and a new one appears where I tried to move it. I did a screen share with an Adobe rep and the same thing happened to him. Then some of my text randomly disappeared on the pages. Fortunately I had a back up file that I am now able to proceed. However I still have the same issue with some of the swirls.
You should not attempt to make this correction in the PDF file. Go back to the original format used to create the book's layout and fix it there, and then create a new PDF file.