Restrict to one booking per staff member in a given timeslot

This issue is a follow up from an issue I posted last month.

In that issue one of your support team had provided me a solution for how to use Webba for the usage case where you have multiple staff that can provide multiple services. The important thing is that when a staff member is booked to provide a service in a given timeslot, that staff member cannot be booked to provide another service in that same timeslot. But another staff member may still be available for booking in that timeslot. The solution given was to use categories for the services and then to add a copy of the service to the category for each staff member.

I had tested the solution and thought it was working, but now looking at it again, I see it is not working. Not sure if something changed on my end or I did not test it properly last month. But, in any case, the problem is that a staff member can be booked again in the same timeslot for another service.

I double checked the configuration provided and I have everything set according to the provided configuration:

1. Create service category for each service: counseling, healing, acupuncture.
2. Create service for each pair service-staff. For example ‘counseling by paul’, ‘healing by Paul’, ‘healing by Christina ‘ … etc
3. On your page use the following shortcode: [webbabooking category_list=yes]
4. Open SETTING – Booking rules and make sure that Autolock bookings option is disabled.
5. Open SETTING – Wording / Translation and set the Service label to ‘Select staff’ and Category label to ‘Select service’.

I am wondering what I am missing, ora different configuration is needed to solve this usage case?