diff --git a/CHANGELOG.md b/CHANGELOG.md
index c74e880c9..44719c24a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ and this project adheres to
 - ♿️(frontend) fix modal aria-label and name #2014
 - ♿️(frontend) fix language dropdown ARIA for screen readers #2020
 - ♿️(frontend) fix waffle aria-label spacing for new-window links #2030
+- 🐛(backend) stop using add_sibling method to create sandbox document
 
 ## [v4.8.1] - 2026-03-17
 
diff --git a/src/backend/core/models.py b/src/backend/core/models.py
index 0cab0945c..d1869e132 100644
--- a/src/backend/core/models.py
+++ b/src/backend/core/models.py
@@ -285,8 +285,7 @@ class User(AbstractBaseUser, BaseModel, auth_models.PermissionsMixin):
                     )
                     return
 
-                sandbox_document = template_document.add_sibling(
-                    "right",
+                sandbox_document = Document.add_root(
                     title=template_document.title,
                     content=template_document.content,
                     attachments=template_document.attachments,
diff --git a/src/backend/core/tests/test_models_users.py b/src/backend/core/tests/test_models_users.py
index cbfa144ed..024d8b0a6 100644
--- a/src/backend/core/tests/test_models_users.py
+++ b/src/backend/core/tests/test_models_users.py
@@ -216,7 +216,13 @@ def test_models_users_duplicate_onboarding_sandbox_document_creates_sandbox():
     When USER_ONBOARDING_SANDBOX_DOCUMENT is set with a valid template document,
     a new sandbox document should be created for the user with OWNER access.
     """
+    documents_before = factories.DocumentFactory.create_batch(20)
     template_document = factories.DocumentFactory(title="Getting started with Docs")
+    documents_after = factories.DocumentFactory.create_batch(20)
+
+    all_documents = documents_before + [template_document] + documents_after
+
+    paths = {document.pk: document.path for document in all_documents}
 
     with override_settings(USER_ONBOARDING_SANDBOX_DOCUMENT=str(template_document.id)):
         user = factories.UserFactory()
@@ -233,6 +239,10 @@ def test_models_users_duplicate_onboarding_sandbox_document_creates_sandbox():
     access = models.DocumentAccess.objects.get(user=user, document=sandbox_doc)
     assert access.role == models.RoleChoices.OWNER
 
+    for document in all_documents:
+        document.refresh_from_db()
+        assert document.path == paths[document.id]
+
 
 def test_models_users_duplicate_onboarding_sandbox_document_with_invalid_template_id():
     """