The Lazy Loading Course Navigation module adds a very simple feature to LearnDash sites: it replaces the default LearnDash Course Navigation widget with one that loads after the rest of the page loads. On sites with a lot of LearnDash posts (courses, lessons, topics and quizzes), this behaviour change can result in pages inside courses loading significantly faster than with the standard Course Navigation widget.
Visit the Lazy Loading Course Navigation knowledge base article for full details.
The course navigation hierarchy on the right side of the page is generated using the Lazy Loading Course Navigation shortcode. It looks identical to the LearnDash widget, but you can see that on a page reload, there’s a momentary progress indicator as the course hierarchy loads asynchronously with the main page.