如何修复无法修改 Wordpress 中的标题信息错误？

当我尝试在自定义插件中进行重定向时，出现错误。我检查了所有文件，<?php标签前没有空格，我没有输出任何数据。禁用其他插件。

wp-1 | [Thu Jul 28 11:49:13.550986 2022] [php7:warn] [pid 24] [client 172.21.0.1:38412] PHP Warning:  Cannot modify header information - headers already sent by (output started at /var/www/html/wp-admin/includes/template.php:2546) in /var/www/html/wp-includes/pluggable.php on line 1424, referer: http://localhost:8081/wp-admin/admin.php?page=kws

插件文件。

function run_countries() {
    $plugin = new Plugin();
    $plugin->run();
}

add_action( 'init', 'run_countries' );

class Plugin {
    public function __construct() {
        // ...
        $this->load_dependencies();
        $this->define_admin_hooks();

    }

    private function load_dependencies() {

        require_once plugin_dir_path( __DIR__ ) . 'inc/class-plugin-loader.php';

        require_once plugin_dir_path( __DIR__ ) . 'admin/class-admin.php';

        $this->loader = new Plugin_Loader();

    }
    private function define_admin_hooks() {

        $plugin_admin = new Admin( $this->get_plugin_name(), $this->get_version() );

        $this->loader->add_action( 'admin_enqueue_scripts', $plugin_admin, 'enqueue_styles' );
        $this->loader->add_action( 'admin_enqueue_scripts', $plugin_admin, 'enqueue_scripts' );

        $this->loader->add_action( 'admin_menu', $plugin_admin, 'add_admin_menu' );
}

}

if ( ! class_exists( 'Admin_Request_Handler' ) ) {
    require_once plugin_dir_path( __FILE__ ) . 'inc/class-admin-request-handler.php';
}
class Admin {
    public function __construct( $plugin_name, $version ) {
        $this->request_handler = new Admin_Request_Handler();
    }
    public function add_admin_menu() {
        add_menu_page(
            'Domains',
            'Domains',
            static::CAPABILITY,
            static::SLUG,
            [ $this->request_handler, 'show_table' ],
        );
}
}

class Admin_Request_Handler {
    public function show_table() {
        $table = new Domains_List_Table();

        $table->process_bulk_action();

        if ( ! empty( $_REQUEST['_wpnonce'] ) ) {
            wp_redirect( remove_query_arg(
                [
                    '_wp_http_referer',
                    '_wpnonce',
                ],
                $_SERVER['REQUEST_URI']
            ) );
        }

        require_once plugin_dir_path( __DIR__ ) . 'partials/page-list.php';
    }
}

还有什么可能的原因？以及如何修复initob_start()以外的其他问题？