Hi,
I tried the basic Avada theme with Fusion Builder and LearnDash plugin.
<a class="btn btn-primary lana-download" href="#" role="button">My link <span class="badge">1</span></a>
The link will appear to me in LearnDash lesson description. It does not look like a button, it’s like a simple link. But it is visible.
I think you have a problem with shortcode processing. Install the Lana Shortcodes plugin and try the button shortcode.
Or send me the exact lesson link where the problem is with the download button (the button should be added).
Or send me limited access to your website, then I can check it.
My email: [email protected]