Secured frontpage won't redirect to default Protected Content page


I have my site set to redirect users to a different page if they don't have permission to view a page. But I cant make this apply to the Frontpage of the site.

The problem exists here:

The page that is acting as the frontpage is:

When visiting this page directly it behaves as intended - but not when visiting as the frontpage.

Please note I have set "frontpage" to protected in "Protection Rules > Special Pages> Frontpage"

Can you please advise how to fix this. I have left support access open.