Я тестировал следующий код на Opencart 3.0.2.0 и отлично работает

Контроллер заголовка (каталог / контроллер / common / header.php)

load->model('setting/extension');

    $data['analytics'] = array();

    $analytics = $this->model_setting_extension->getExtensions('analytics');

    foreach ($analytics as $analytic) {
        if ($this->config->get('analytics_' . $analytic['code'] . '_status')) {
            $data['analytics'][] = $this->load->controller('extension/analytics/' . $analytic['code'], $this->config->get('analytics_' . $analytic['code'] . '_status'));
        }
    }



    if ($this->request->server['HTTPS']) {
        $server = $this->config->get('config_ssl');
    } else {
        $server = $this->config->get('config_url');
    }

    if (is_file(DIR_IMAGE . $this->config->get('config_icon'))) {
        $this->document->addLink($server . 'image/' . $this->config->get('config_icon'), 'icon');
    }

    $data['title'] = $this->document->getTitle();

    $data['base'] = $server;
    $data['description'] = $this->document->getDescription();
    $data['keywords'] = $this->document->getKeywords();
    $data['links'] = $this->document->getLinks();
    $data['styles'] = $this->document->getStyles();
    $data['scripts'] = $this->document->getScripts('header');
    $data['lang'] = $this->language->get('code');
    $data['direction'] = $this->language->get('direction');

    $data['name'] = $this->config->get('config_name');

    if (is_file(DIR_IMAGE . $this->config->get('config_logo'))) {
        $data['logo'] = $server . 'image/' . $this->config->get('config_logo');
    } else {
        $data['logo'] = '';
    }

    $this->load->language('common/header');

    // Wishlist
    if ($this->customer->isLogged()) {
        $this->load->model('account/wishlist');

        $data['text_wishlist'] = sprintf($this->language->get('text_wishlist'), $this->model_account_wishlist->getTotalWishlist());
    } else {
        $data['text_wishlist'] = sprintf($this->language->get('text_wishlist'), (isset($this->session->data['wishlist']) ? count($this->session->data['wishlist']) : 0));
    }

    $data['text_logged'] = sprintf($this->language->get('text_logged'), $this->url->link('account/account', '', true), $this->customer->getfirstName(), $this->url->link('account/logout', '', true));

    $data['home'] = $this->url->link('common/home');
    $data['wishlist'] = $this->url->link('account/wishlist', '', true);
    $data['logged'] = $this->customer->isLogged();
    $data['account'] = $this->url->link('account/account', '', true);
    $data['register'] = $this->url->link('account/register', '', true);
    $data['login'] = $this->url->link('account/login', '', true);
    $data['order'] = $this->url->link('account/order', '', true);
    $data['transaction'] = $this->url->link('account/transaction', '', true);
    $data['download'] = $this->url->link('account/download', '', true);
    $data['logout'] = $this->url->link('account/logout', '', true);
    $data['shopping_cart'] = $this->url->link('checkout/cart');
    $data['checkout'] = $this->url->link('checkout/checkout', '', true);
    $data['contact'] = $this->url->link('information/contact');
    $data['telephone'] = $this->config->get('config_telephone');

    $data['language'] = $this->load->controller('common/language');
    $data['currency'] = $this->load->controller('common/currency');
    $data['search'] = $this->load->controller('common/search');
    $data['cart'] = $this->load->controller('common/cart');
    $data['menu'] = $this->load->controller('common/menu');

    return $this->load->view('common/header', $data);
}
}

Языковой файл (каталог / язык / общий / header.php)

Welcome %sLogout';

Вид заголовка (каталог / просмотр / тема / по умолчанию / шаблон / общий / header.twig)

{% if description %}

{% endif %}
{% if keywords %}

{% endif %}






{% for style in styles %}

{% endfor %}
{% for script in scripts %}

{% endfor %}

{% for link in links %}

{% endfor %}
{% for analytic in analytics %}
{{ analytic }}
{% endfor %}








{% if logo %}

{% else %}
{{ name }}
{% endif %}

{{ search }}
{{ cart }}



{{ menu }}

Результат: opencart-welcome-message-screen