I found a conflict between the theme (Choice) and the plugin Post Type Order, which is the plugin that you suggested in the forum to use to sort the portfolio-items in a Portfolio, as the theme does not have this feature. When the plugin is installed you can not insert shortcodes in posts, pages and portfolio items. Have you any idea how to fix it? Obviously, it would be nice to be able to use both features (sort portfolio-item and insert shortocodes).
Another question. Is there a way to sort the portfolio-categories in a portfolio?
Thank you for your support