Why many tables are displayed as already booked?

Hello support team, Thank you for developing the free MyTicket Events plugin. Unfortunately, we currently have a small problem where we don't exactly know what the problem is. https://derweinsommer.de/reservierung/When you visit the page and open it for the first time, many tables are displayed as already booked. Only the change of date to another date and then back to the starting date shows the correct allocation. Have you any ideas?