Problems With The Locations/Services/Service Provider Relationship

I have been having the following issue with this plugin and am hoping I'm doing something wrong

The website is for a medical center which is located in 3 separate cities:

Cork, Sydney, Sofia

I have added these as locations.

The services offered in these locations include Dentistry and a Doctors Surgery.

I have added these as services. When adding these services I have selected the location associated with the service.

In Cork there is both a dentist and a doctor. When I attempt to book an appointment I first go to select the location and see a drop down menu with:

Cork
Sydney
Sofia
Cork

Any idea why Cork would appear twice? I am setting up the plugin so this is only a small example and there are more locations to be added and more services (up to 24 in some locations) so if someone needs to scroll through 24 instances of Cork or another city when selecting a location it will quickly become pointless.

Any advice? Any simple setting I've missed?