Some businesses run more than one address, and some professionals work from a different place on different days — a salon midweek, a home studio at weekends, a chair they rent on Saturdays. The booking page shows which location a time belongs to, and so does your confirmation.
Read the address on the confirmation rather than going where you went last time. Turning up at the right studio on the wrong side of town is the most common way to miss an appointment, and it counts as a missed appointment.
Prices and availability can differ by location for the same service, because the rent differs. The price you see is the price for the location you are booking.
If you have a preference, book the location rather than the earliest slot, and add it to your calendar with the address attached so the reminder carries it.