AHH! I have been working on a handout and when I copy the words from one page to another, there is a white highlighting. I have marked "no highlight" ... but still, it highlights.
Here is the solution I found.
Choose "Clear Formatting". It removes all the formatting so I had to redo the Heading 2 Style that I was using ... but it worked. It is on the home tab and looks like a little eraser, and in the Styles Pane.