Hi Waldo,

That is how they should work, they work the same in every WordPress theme because that is the WordPress logic.

Anyway, If you want to reverse their order, then:

Please go to Appearance > Editor > and make sure that Theme Functions (functions.php) file is selected.

Then at the end of the current codes please add this PHP code:

add_filter( 'kalium_adjacent_post_link_args', function ( $args ) {
   $args['prev'] = ! $args['prev'];
   $args['next'] = ! $args['prev'];
   return $args;
} );

Have a nice day!