We fixed several problems that could appear when two customers book the same appointment time at almost the same moment.
- Choosing an appointment time that another customer is holding during checkout no longer fails with Class is no longer available - the booking now goes through in its own session.
- Places held during checkout are now counted correctly against the time slot, including on sessions that already have confirmed attendees, so a time no longer looks free when it is not.
- Leaving or abandoning checkout now releases only the places you were holding, instead of cancelling holds belonging to other customers who are still paying.
