Serial Appointment with all day mark

Hello,
We have a problem with Exchange calendar synchronization via ActiveSync.
Existing serial appointments that are marked all day are not displayed in the top level but block the whole day with an appointment.
When I open the appointment and check the all day option it is marked out, but in Outlook it is marked.
After setting the mark, the appointment moves to the top level.
Can someone help me with that?

Best Regards
Marc