Preview: highlights moving after saving
Since updating to El Capitan, the highlights that I apply to PDFs in Preview sometimes move when I save the PDF. Once they move, I cannot put them back. The highlights no longer correspond meaningfully to the text to which they were originally applied (see screenshot below). This makes the PDF be functionally useless.
Does anyone have any idea why this is happening or what I can do about it?
MacBook Air, OS X El Capitan (10.11.1)