听起来您已经配置了DNS，这样app.example.com CNAME记录指向了Cloud Storage.相反，您需要一个app.example.com A记录，指向您的负载均衡器的IP地址.

It sounds like you've configured DNS such that an app.example.com CNAME record points to Cloud Storage. Instead, you need an app.example.com A record that points to your load balancer's IP address.