When a Perspective session is launched form the Designer, it will ALWAYS launch to /. If you want to configure a different page to launch to from the Designer, it should be configured to use the / path. If you want sessions to launch to a certain page, then you should configure your Session Startup Event to perform the desired navigation to the page of your choice.
From the Docs:
Perspective is designed to operate in a web browsing environment. A Page is the main navigational element in a Perspective Session, so when a Perspective Session starts, it typically begins at the page mounted to the Page URL "/" . The exception to this being cases where the user manually enters a different Page's URL into the address bar of their browser.