User installs Web clip App Center App, and then attempts to access App Center. Instead of receiving App Center login page, user returns to Web clip download page.
This issue occurs when SAML is enabled as external IDP in App Center. If the SAML sequence includes any calls to a third-party authentication provider (e.g., "Login with Google"), then depending on how that page was developed, this may cause an external Safari launch. This is by Apple's design for Web clip apps. As a result, App Center session information is lost (since Safari is a new browser in a new process), and the Web clip download page appears again instead of the App Center login.
[Sasha -- please provide solution or proposed workaround]