Accessing Instagram Individual Pages through Zscaler

I am trying to access Instagram individual pages (e.g. through ZIA on Windows 10 (the browser is Chrome). Without logging in Instagram and trying to access the page with putting the URL into an address bar directly, I get an error message saying “Sorry, this page isn’t available.” On the other hand, after logging in Instagram, accessing the page is successful and the content is displayed. I wonder why such difference occurs. Does anyone encounter the same issue and know how to troubleshoot?

I added to the authentication exemption list and it works for us