I have Adobe Acrobat DC Pro and it does not recognize existing text on PDF to allow me to strike through it. The PDF has a list of items to be used. I am tasked with writing the actual quantity used in red beside the original list quantity that is to be struck through in red. This program does not recognize that original text in the comment mode and when I try to strike through the original quantity numbers it only strikes out my corrective quantities entries. There is another worker that has Adobe Acrobat 2017 and he has no issue doing this and I am operating it just like him but in my case the program seems to ignore those original text. Is this a bug or my ignorance of some feature I need to enable?