Hi. If you tallk about single article page and want bg image in this area...
... add full article image in an article settings (Images & Links tab).
Page Title is not display at all on the article pages, so it is pointless to configure this for a separate article.
And by the way, if we talk about bugs, hiding this only through CSS is bad for SEO. Joomshaper should look at it and additionally hide it (remove completly from output code) through JS or PHP.
Antoni, while Joomshaper will deal with this, I would recommend that you create a custom.js file, following Helix documentation, and add the following code there:
jQuery(function ($) {
$('.view-article #sp-title').remove();
});