Plugin renders in preview but shortcode shows when published

find the function that generates the output, or the output itself if it’s hardcoded in your page and add this function to it:

<?php echo do_shortcode( $content ) ?>

if your content is generated through the_post(), it’ll be:

<?php echo do_shortcode( the_post() ) ?>

or the_excerpt:

<?php echo do_shortcode( the_excerpt() ) ?>