try on try SearchController

config/config.yml.dist

 IdBookEngine : "b68c6848-b7d9-4083-91f0-3de6f065280e"
 form_template: "elloha/form.html.twig"
+results_elloha_template: "elloha/results.html.twig"
 searchable_contenttypes:
     - HCO
     - HLO

src/Controller/Frontend/SearchController.php

@@ -75,9 +75,16 @@ class SearchController extends Base
             $idsProduct = $this->ellohaRequest->getIdProducts();
             $results = $this->_searchReservableContents($idsProduct, $formData);
 
-            return $this->render('@elloha/Frontend/search/results.html.twig', [
-                'results' => $results
-            ]);
+            try {
+                return $this->render($this->config['results_elloha_template'], [
+                    'results' => $results
+                ]);
+            } catch (\Exception $e) {
+                return $this->render('@elloha/Frontend/search/results.html.twig', [
+                    'results' => $results
+                ]);
+            }
+
         }
     }