Fix correct langcode.

Closes #3495494

src/Plugin/CustomField/FieldFormatter/HierarchicalFormatter.php

@@ -136,6 +136,7 @@ class HierarchicalFormatter extends EntityReferenceFormatterBase {
 
     $formatter_settings = $settings['formatter_settings'] + static::defaultSettings();
     $tid = $entity->id();
+    $langcode = $entity->language()->getId();
     $term_tree = [];
 
     switch ($formatter_settings['hierarchy_display']) {
@@ -187,8 +188,8 @@ class HierarchicalFormatter extends EntityReferenceFormatterBase {
     $term_tree = array_filter($term_tree);
 
     foreach ($term_tree as $index => $term) {
-      if ($term->hasTranslation($item->getLangcode())) {
-        $term_tree[$index] = $term->getTranslation($item->getLangcode());
+      if ($term->hasTranslation($langcode)) {
+        $term_tree[$index] = $term->getTranslation($langcode);
       }
     }