Having difficulties with WP cron

You can add debugging statements to your code to verify if the cron job is being scheduled and executed correctly. like you can use error_log() to log messages to the PHP error log:

public function schedule_event() {
if (!wp_next_scheduled('redirection_checker_hook')) {
    error_log('Scheduling redirection_checker_hook');
    wp_schedule_event(time(), 'every_three_minutes', 'redirection_checker_hook');
}
}

public function redirection_checker_func() {
error_log('Running redirection_checker_func');
update_option('test_option', 'success');
}