In Confluence, when the administrator configures the application to use a custom default homepage, the same will be displayed on the sidebar, but, the user will still be redirected to the All Activites by default. However, if the same select the "Activites tab", or, "Your Work", the next time that the same clicks on the Confluence logo (to be redirected to the dashboard), it will redirect the user to the last option that was selected, including the new custom homepage.

This is a suggestion to always make the new configured page to become the default one as this can impact on the usability for external users, or, even anonymous users that will not be redirected to the custom homepage