How to prevent Featured Image on Portfolio section from repeating on Portfolio page in Zelle

Important notice: This product is now in maintenance mode and is no longer being actively developed or supported. Updates and bug fixes will not be provided unless they relate to security concerns.

The best of doing it would be using a child theme. So first create a child theme and copy content-portfolio.php file to your child theme and remove the following code from it:

<?php
if ( has_post_thumbnail() ) {
    the_post_thumbnail('full');
}
?>

And that will do the job.