Return URL for aliased routes

Hello. I have a collection of guides that are available for members with a certain tag. The page that displays these guides uses routes of the type guides/[slug:s] so that I can use the same page for all of them. the default location of this page is /guides/guide. So when members not having the tag, try to access it, they get redirected to the login page but the return url value instead of being the one of the specific guide they tried to access, is the default one (/guides/guide) which of course is empty.

Is this expected to be like this or am I doing something wrong here?

Thanks!