Prevent user booking multiple places in a group class

Hi there

I run a website for a tennis club. We have a social session that we are using Squarespace Scheduling for. The sessions are free to attend but spaces are limited. Frequently the sessions are fully booked.

I've noticed that some members are accidentally booking multiple spaces, which is disrupting the sessions due to odd numbers of people showing up. Members are using the same name, mobile number and same email address to make these accidental bookings.

I would like to limit members to one booking per session.

In calendar scheduling limits, 'Appointments Per Time Slot' is set to 1, which I assumed that would stop this from happening. But it doesn't.

Does anyone know how I can stop this from happening? I would've hoped that Squarespace would notice the repeat email address or mobile number and prevent the booking going through but that doesn't seem to work. My club's members are unlikely to create accounts.

In case it helps, the URL is: https://www.eshertennis.co.uk/padel-mixin

Thanks in advance.