Booking Calendar double-booking

Our booking calendar is double-booking. Calendar shows a reserved timeslot (January 10 @ 1:00 pm) but a different customer just tried booking it as well. According to our WIX website, both the 10:30 and 1:00 appts are available, but our booking calendar clearly shows that 1:00 is taken. How do I fix this? I have checked all of the settings and everything seems fine. Also, when I click our website, pretending to book a party, the form is already filled out with a previous customer’s information. I am so confused.