I tried to highlight a couple of words in my NKJV on my iPad, and it ended up not only highlighting the entire letter of 1 Peter, but proceeded to do so on all other versions (they are linked), not to mention transferring to my iPhone as it synced.
Never mind. I found that I selected the entire letter as an anchor in the notes. Once I removed it, the highlight disappeared everywhere, except for the two words I originally highlighted. I need to learn how to use the notes section and anchors.
