Read Out Loud- Only Reading 1 Page at a Time?

Good afternoon, I have tried everything my PDF document is 150 pages. I have changed the prefernces in Reading to "Read the Entire Document." as needed for large files over 50 pages. 

And still when I click Read to the End of Document under "Read Out Loud". It will only read 1 page at a time?? Hoping the document to auto scroll and read the entire 150 pages. 

I have tried rebooted and restarted after setting changes. 

Thank you for your help.