Highlighter Tool not working accurately

When I highlight a word or phrase and then go to my Unassigned Folder to edit it and put it into the appropriate notebook, the highlighted word or phrase shown is not what I originally highlighted. It is a word or two "off". How do I resolve?

Also, when I try to "re-highlight" I can't get the Highlighting start and finish markers go where I want them to go. How do I resolve?

I believe your problem could be related to issues other people have reported in this forum. For example, see Highlighting is inconsistant between platforms/browsers.