Adobe pdf not showing as Completed when opened and scrolled through

We have a curriculum with 3 courses included. One is a pdf file that we want the trainees to open and scroll through. Something has changed as we do not get a completion status on the course when users open and scroll through. We are on an on-premise deployment. Connect version 9.1. This came from a Word 2010 document converted to pdf. The Acrobat version displaying is 11.00.06. Any suggestions on how to get around this?