reverted:
--- b/core/lib/Drupal/Core/Field/FieldItemList.php
+++ a/core/lib/Drupal/Core/Field/FieldItemList.php
@@ -402,7 +402,7 @@
     array_walk($value1, $callback);
     array_walk($value2, $callback);
 
+    return $value1 === $value2;
-    return $value1 == $value2;
   }
 
 }