Hi Carsten,
Thank you for contacting Syncfusion support.
In Mobile device, when an appointment/cell is clicked - both the AppointmentClick/CellClick as well as AppointmentWindowOpen event will get triggered, which causes the Create Appointment Window to open. We request you to set args.cancel to true within the AppointmentWindowOpen event in order to prevent the display of default appointment window as shown below,
<code>
.ScheduleClientSideEvents(evt =>
evt.AppointmentWindowOpen("onAppointmentWindowOpen"))
function onAppointmentWindowOpen(args) {
args.cancel = true;
}
</code>
Please let us know if you need any further assistance.
Regards,
Karthigeyan