Board Thread:Support Requests - Designing Your Wiki/@comment-11341031-20170610214117/@comment-9605025-20170625203829

That is because it is using the actual MediaWiki caption parameter. This will use the provided caption for both the 'title' and 'alt' HTML attributes. This manifests itself in different ways depending on the browser. For Internet Explorer, it shows up as hover text. If you want to have it below the image as in the original infobox, you should use the following.