In general, the reason is that the text in the pdf metadata is different from the text in page you can see. After open the pdf file in Foxit Reader, you can go to View>Text Viewer to enter into text viewer mode for viewing the document as a text file, please confirm if the incorrect text you get in the viewer mode is same with the one in Text Viewer.
Also to double check, you can try to open your pdf file in other PDF Viewer,such as Microsoft Edge , copy and paste the text to see if you get the same case.
