By default the wordpress categories hierarchy are shown with the “checked” categories on top as in the demo image here :

If you need to show the checked categories beneath their parents you will need to add the following in your functions.php or create a plugin with the following code .

function checklist_args( $args ) {

    $args['checked_ontop'] = false;

    return $args;
  }
  
add_filter( 'wp_terms_checklist_args','checklist_args');

Which will make it list as in the picture below:

Keep it real ,
Best Regards ,Alin Razvan
I'm a small fish in a big ocean , trying to make a difference and some waves while swimming my way through .