Routing issues with filters

Referencing https://codeigniter.com/user_guide/incoming/routing.html#nesting-groups and the code exmaple:

<?php

$routes->group('admin', ['filter' => 'myfilter:config'], static function ($routes) {
    $routes->get('/', 'Admin\Admin::index');

    $routes->group('users', ['filter' => 'myfilter:region'], static function ($routes) {
        $routes->get('list', 'Admin\Users::list');
    });
});

Run this using spark

php spark serve --port 28080

I cannot get this to work as expected when the name of the filter options are the same, see on the config filter is executed.

If replaced with a second filter myfilter2 it works