Find an element on a PDF

I am working through the foundation videos and got stuck at Lesson 10 where they process an invoice.

According to the video they are able to select just the ‘Grand Total’ and the amount. When I try to do it it selects various other data such as the ‘Credit’ field and the amount - see attachment.

Is it a setting problem on my PC or do you experience the same problem.

Sample Invoice A.pdf (381.2 KB)