SOLVED: Shortcode to display Divi project filtered by tag in WP Query loop

SOLUTION: I looked through Divi’s functions.php & saw that the term for the project tags is 'project_tag', so when I amended my $query args it now works!
Thank you very much to everyone who responded 🙂

$query_args = array(
  'post_type' => 'project',
  'post_status' => 'publish',
  'order' => 'DESC',
  'orderby' => 'date',
  'posts_per_page' => '3',
  'project_tag' => $tag
);