still problems with appointments

Hi

I asked for support before but get no answer anymore. So here is my question again.
When i load the appointment page to make an appointment the first time the page shows the correct time table. But when i change the kind of appointment the agenda is empty and people can make appointments on not available time.
I think I did everything you told me but still have the problem. Also the page is very slow loading. I know my whole page is not that fast, but this page is the champion.

Hope you wanna help me some more

Grtz Marion