I found a solution/ workaround to this on the creators website in the comments. I tried what is listed below and it worked for me:
Ok, I figured out how to order them by date. Go to Plugins > Editor. Select WP Featured Content Slider. Under Plugin Files select “wp-featured-content-slider/content-slider.php”. Scroll down the file content until you come to the custom database query. When you see this line “AND (wposts.post_type = ‘post’ OR wposts.post_type = ‘page’);” highlight the whole line and paste this over it:
AND (wposts.post_type = ‘post’ OR wposts.post_type = ‘page’)?ORDER BY wposts.post_date DESC“;
https://www.iwebix.de/featured-content-slider-wordpress-plugin
