Please add the widget with shorcode
Recent Posts
inside a editor widget which is placed to a SigeOrigin Page Builder row.
We also create a post and a YouTube video: http://tiptoppress.com/how-category-posts-widget-work-with-siteorigin-page-builder/
For WordPress +5.0 and Gutenberg you have to install the WordPress widget ‘Classic Editor’ even if you shouldn’t see any posts.