Why does Proxy Server sometimes not display the warning page when trying to access blacklisted websites?
When you connect to an unencrypted blacklisted website via HTTP, Proxy Server will redirect you to a warning page to indicate that the website cannot be accessed.
Modern web browsers do not allow these types of redirect methods when trying to connect to encrypted websites via HTTPS. In this case, Proxy Server will just disconnect from the blacklisted website when Proxy Server is unable to show the warning page.