diff -u b/src/Plugin/ConfigFilter/IgnoreFilter.php b/src/Plugin/ConfigFilter/IgnoreFilter.php
--- b/src/Plugin/ConfigFilter/IgnoreFilter.php
+++ b/src/Plugin/ConfigFilter/IgnoreFilter.php
@@ -175,8 +175,7 @@
       if (!array_key_exists($name, $data)) {
         $data[$name] = [];
       }
-      $name_data = isset($data[$name]) ? $data[$name] : [];
-      $filtered_data[$name] = $this->activeRead($name, $name_data);
+      $filtered_data[$name] = $this->activeRead($name, $data[$name]);
     }
 
     return $filtered_data;