The highlight feature was designed for active use on a mobile device, such as helping a teacher keep their place during a lesson. The highlights are temporary and do not save to the lesson, and they do not show up when printing.
That said, you are able to print only a small selection of the page. To do so, click and hold/drag with your mouse to create a text selection, then right-click the selection and choose Print. Only the selection will show up in your print window.
Customer support service by UserEcho