Problem of highlighted text and comment section

Dear community,

I used the highlight tool to save many parts of a book I was reading in Adobe Acrobat Reader. However, when I went to the comments section, where it normally saves all the highlighted text as pieces of comments, only parts of the highlights were saved as text excerpts. The rest appears just as 'highlighted text' without the text excerpt. Thus, when I request a file only with the excerpts from the comment section, obviously only part of the excerpts appear, and the rest is just an indication of a highlight. So, what should I do to resolve this?