Check for array type.

src/TranslationManager.php

@@ -482,7 +482,7 @@ class TranslationManager {
 
     foreach ($search_keys as $key) {
       // Check 1st level values.
-      if (isset($config_item[$key]) && strlen($config_item[$key]) > 0) {
+      if (isset($config_item[$key]) && !is_array($config_item[$key]) && !empty($config_item[$key])) {
         if ('name' === $key && in_array('label', array_keys($translatable_fields), TRUE)) {
           // Do not translate 'name' if 'label' already present.
           // Workaround for drupal/admin/config/media/image-styles translation.