If your page builder uses shortcodes to save its data, you will have to add this code to your functions.php file of your child theme (see below).
It will run your shortcodes so SEOPress will be able to generate the automatic meta description for you.
Warning: running shortcodes may break your sites. Clear you cache if necessary and test each page carefully.
This code offers an example for Oxygen page builder. By entering %%oxygen%% as a dynamic variable in the meta description template (SEO, Titles and metas, Post types / Taxonomies), the function ct_template_output will be executed. The second snippet uses the Oxygen shortcode to get the post content only. Take the one that best suits your needs.
Modify these variables according to the page builder used. This code is only required if your page builder uses shortcodes to save its data.
Hook name: "seopress_titles_template_variables_array", "seopress_titles_template_replace_array"
Required version: 3.6.2