diff --git a/backend/open_webui/models/oauth_sessions.py b/backend/open_webui/models/oauth_sessions.py
index fbcd763f3..68b2eeb0f 100644
--- a/backend/open_webui/models/oauth_sessions.py
+++ b/backend/open_webui/models/oauth_sessions.py
@@ -135,6 +135,7 @@ class OAuthSessionTable:
                 db.refresh(result)
 
                 if result:
+                    db.expunge(result)  # Detach so dict swap is never flushed
                     result.token = token  # Return decrypted token
                     return OAuthSessionModel.model_validate(result)
                 else:
diff --git a/backend/open_webui/utils/oauth.py b/backend/open_webui/utils/oauth.py
index b23c5c90a..6e59317f8 100644
--- a/backend/open_webui/utils/oauth.py
+++ b/backend/open_webui/utils/oauth.py
@@ -1706,17 +1706,22 @@ class OAuthManager:
                 db=db,
             )
 
-            response.set_cookie(
-                key="oauth_session_id",
-                value=session.id,
-                httponly=True,
-                samesite=WEBUI_AUTH_COOKIE_SAME_SITE,
-                secure=WEBUI_AUTH_COOKIE_SECURE,
-            )
+            if session:
+                response.set_cookie(
+                    key="oauth_session_id",
+                    value=session.id,
+                    httponly=True,
+                    samesite=WEBUI_AUTH_COOKIE_SAME_SITE,
+                    secure=WEBUI_AUTH_COOKIE_SECURE,
+                )
 
-            log.info(
-                f"Stored OAuth session server-side for user {user.id}, provider {provider}"
-            )
+                log.info(
+                    f"Stored OAuth session server-side for user {user.id}, provider {provider}"
+                )
+            else:
+                log.warning(
+                    f"Failed to create OAuth session for user {user.id}, provider {provider}"
+                )
         except Exception as e:
             log.error(f"Failed to store OAuth session server-side: {e}")