https://github.com/opencart/opencart/issues/12661

upload/admin/controller/sale/order.php

@@ -1202,7 +1202,6 @@ public function info(): void {
 
 		// 3. Add the request GET vars
 		$store->request->get['route'] = 'api/order.load';
-		$store->request->get['language'] = $data['language_code'];
 
 		// 4. Add the request POST var
 		$store->request->post = $this->request->post;
@@ -1344,7 +1343,6 @@ public function call(): void {
 
 			// 4. Add the request GET vars
 			$store->request->get['route'] = 'api/' . $call;
-			$store->request->get['language'] = $language;
 
 			// 5. Add the request POST var
 			$store->request->post = $this->request->post;

upload/admin/model/setting/store.php

@@ -208,8 +208,6 @@ public function createStoreInstance(int $store_id = 0, string $language = '', st
 		$request->server = $this->request->server;
 		$request->cookie = [];
 
-
-
 		// Request
 		$registry->set('request', $request);
 
@@ -236,10 +234,14 @@ public function createStoreInstance(int $store_id = 0, string $language = '', st
 		$registry->set('template', $template);
 
 		// Adding language var to the GET variable so there is a default language
-		$request->get['language'] = $language;
+		if ($language) {
+			$request->get['language'] = $language;
+		} else {
+			$request->get['language'] = $config->get('language_code');
+		}
 
 		// Language
-		$language = new \Opencart\System\Library\Language($config->get('language_code'));
+		$language = new \Opencart\System\Library\Language($request->get['language']);
 		$language->addPath(DIR_CATALOG . 'language/');
 		$language->load('default');
 		$registry->set('language', $language);

upload/catalog/controller/api/order.php

@@ -65,8 +65,6 @@ public function save(): void {
 			$this->session->data['order_id'] = 0;
 		}
 
-
-
 		// Customer
 		$this->load->model('account/customer');