Add arguments to get_the_terms for custom post types

get_the_terms uses wp_get_object_terms with defaults, which is orderby name ascending. You can use wp_get_object_terms directly if you want to set arguments differently.

$args = array(
    'orderby' => 'term_id'
);
$terms = wp_get_object_terms( get_the_ID(), 'category', $args );