--- a/core/modules/config/src/StorageReplaceDataWrapper.php
+++ b/core/modules/config/src/StorageReplaceDataWrapper.php
@@ -44,6 +44,7 @@
   public function __construct(StorageInterface $storage, $collection = StorageInterface::DEFAULT_COLLECTION) {
     $this->storage = $storage;
     $this->collection = $collection;
+    $this->replacementData[$collection] = [];
   }
 
   /**
@@ -164,8 +165,10 @@
    * {@inheritdoc}
    */
   public function createCollection($collection) {
-    $this->collection = $collection;
-    return $this->storage->createCollection($collection);
+    return new static(
+      $this->storage->createCollection($collection),
+      $collection
+    );
   }
 
   /**