Lubica,
If they are disappearing, it is probably because you are inserting empty tags like <p></p> to insert spaces. The theme filters out these as unwanted p tags generated by WordPress (well known issue with WP shortcodes). Pls use margins and paddings in CSS to create spaces. The theme does not filter out <br> or blank spaces tags since they have valid use. Will need a temp login to your site with the page where this is happening so that I can debug this. Thanks