WP cron job is not triggering a custom plugin

I am working on a class-based plugin. I need a custom cron job that will be active when the plugin is active and run the plugin function. Now, I am facing an issue where it is not calling the plugin function, but I have checked the cron that has already been created. Below is my code. Let me know what I am missing here. smcp_cron_do_task() is not triggered by the cron job.

Also, I'm testing it in my local Docker system.

class ClassName {

    public function __construct() {
        // Ensure custom cron intervals are registered early
        add_filter( 'cron_schedules', array( $this, 'add_custom_intervals' ) );

        // Hooks
        register_activation_hook( __FILE__, array( $this, 'smcp_cron_activate' ));
        register_deactivation_hook( __FILE__, array( $this, 'smcp_cron_deactivate' ));

        add_action( 'smcp_cron_task_hook', array( $this, 'smcp_cron_do_task' ) );
    }

    // Schedule on activation
    function smcp_cron_activate() {
        if ( ! wp_next_scheduled( 'smcp_cron_task_hook' ) ) {
            wp_schedule_event( time(), 'every_minute', 'smcp_cron_task_hook' );
        }
    }

    // Clear scheduled event on deactivation
    function smcp_cron_deactivate() {
        $timestamp = wp_next_scheduled( 'smcp_cron_task_hook' );
        if ( $timestamp ) {
            wp_unschedule_event( $timestamp, 'smcp_cron_task_hook' );
        }
    }

    function smcp_cron_do_task() {
        // Custom Code
        error_log( 'My custom cron job ran at: ' . current_time('mysql') );
    }

    public function add_custom_intervals( $schedules ) {
        $schedules['every_minute'] = array(
            'interval' => 60,
            'display'  => __( 'Every Minute' ),
        );
        return $schedules;
    }
}

// Initialize plugin
new Site_Monitor();

I want to trigger this smcp_cron_do_task() by the cron job.