Duplicate bookings with "Out of stock" status.

Good day! I have a strange situation. I set it up that I only have 1 apartment and it can be bought only once a day and in the settings it is clear that everything is correct.

Suddenly, I receive a notification that a customer has made an order for a date that is already taken. I contacted the client in an attempt to resolve the issue, and as it turned out, the client on the site had selected and booked. I looked, and, indeed, despite the fact that there is data on the first booking and the second booking, the site gives permission to book again for the same dates. We closed the sale of the room on this date by selecting "sold out". However, after 2 weeks, the site again "sold" the apartment on this date

As you can see, it is even written that it was booked 2 times. Why is that?! Why does the program allow clients to do this. We rent apartments only through Booking, other services are not configured.

The difference between bookings is several days.

Thank you in advance