Change sign-up pages so that they honor the tier requirements of the access group

I set up an access group and restricted access to people in my highest tier. I then set up a sign-up page for the access group.

If someone in a lower tier gets a hold of the sign-up page link, they can join the access group even though their tier status should exclude them from that group.

Please make an urgent change so that sign-up pages honor the tier requirements of their associated access group.