Appointments + Login not showing

During the appointment booking process, the login portion will not show. I have "Login Required" set to yes, and "Accept login from Front End" selected.

If I am signed in to the site as an admin, I am able to see the plugin in action. If I sign out, and re-visit the page, the plugin disappears. I assume this is because of the "Login Required" aspect. If I change the setting to No Login Required, then I can see the plugin in action as a logged out user.

I would like the functionality that is supposed to happen, where the client visits the page, selects an appointment and then is directed to login.

I have checked the page, and the shortcode is there for [app_login], to rule that out. Every other aspect of the plugin is working fine, except for that.

What am I missing or doing wrong?