Wix Bookings One Group Per Time Slot

I am using Wix bookings with the class service type. The goal is to allow a client to book for himself or up to our class size limit, which is 32 people. In the Booking Policy, I turned on the option for group bookings up to that limit.

The issue I am running into is the scenario where the client only takes 10 of the 32 spots, which leaves 22 open. I want to only allow one group per session, even if it is not full.

Doing research, I have seen where people have turned on that exact option to only allow one booking per time slot, but I do not see that option anywhere with any of the service types.

Has that option been removed? Is there another workaround?

Thank you in advance.