and therby get access to this specific page, even though am not logged in.
I have in bubble editor settings activated "Limit access to this app . . . . " and then my app is protected
but, i just wonder why the link (se above) is shown in the first place.
If your privacy settings block content for people not logged in it’s pretty safe. Even if it takes a split second to redirect the page your sensitive content will be blocked. As an added measure you can add a constraint to all the elements on the page to not be visible if current user isnt logged in as well.