Broken link

Why do I have this strange highlighting? 
This is because of our FAQ functionality, where we highlight search terms.

What's the problem?
Both these links work in preview mode - they go to the intended url:
However, in live, the second one goes to

What appears to be the underlying cause?
The original html for the broken link is:

           <a href=\"\" target=\"_blank\">
                 <u><span style=\"background-color:#FDCB2E\">family-permit</span></u>

By looking at 'view-source' in live, it appears that things are added, including an auto-recognition link which is wrapped around the second link and which is the culprit.

           <a href="" target="_blank">
                <u><a data-auto-recognition="true" href="" target="_blank"></a>
<span style="background-color:#FDCB2E">family-permit</span></u>

How do I prevent this from happening?