This is indeed a bug, either server or UX, possibly server. I saw the same thing on I can't take the tour on this meta.
It came up that tours are important, which is why it should remain on new meta accounts.
A badge is offered, but not available. The link indicates a tour on a meta site, but redirects to the meta's main tour page, but the meta profile still invites the badge.
This is might remotely be a server setting problem with subdomain redirects in https, similar to the issue I raised here: Apache .conf to redirect all http subdomains to corresponding https subdomains via wildcard alias.
It is more likely a UX bug, since many forums indicate that there should be no tour for meta, in which case main side code was ported to the meta site.