There is a major bug, most people will be using this to have their own start page, the issue is, when you click any link from this new tab page, it loads it in its iframe and dousnt redirect to the proper website you have clicked.
Unfortunately this is a known issue (https://github.com/MethodGrab/firefox-custom-new-tab-page/issues/1) with no easy solution unless you control the site used as your new tab page. If you do control the site you can add `target="_top"` to the links to make them open in the top frame.
I've added a note about this to the caveats section of the add-on description.
