Problems highlighting wrong word

Iæm having trouble with highlighting in Adobe Acrobat Reader, it will work fine for one part of the ducument, then it suddendly starts highlighting at the following word (not the word I'm trying to highlight). The highlighting also end one word further than I'm trying to end it.

If anyone has any solution to this issue, I would be very grateful! I now have to save, close the document and reopen it whenever this happens (which is a lot of times).