Cause: After you enable access to a private bucket, signature information is included by default for non-anonymous access when you retrieve an object from OSS by using CDN. However, to access the default homepage configured by using static website hosting, the request must be anonymous.
To resolve this, configure a URL rewrite rule on the Alibaba Cloud CDN console. Set Path to Be Rewritten to ^/$ to match the root directory, Target Path to /index.html, and the Flag to Redirect.
After the configuration is complete, when a client requests www.example.com/, an Alibaba Cloud CDN point of presence (POP) returns the HTTP 302 status code to the client to re-request www.example.com/index.html.
For more information about how to configure URL rewrite rules, see Access URL Rewrite.