Hi Anass,
Greetings from Syncfusion support.
We have validated your reported query “How would I go about disable dragging and dropping event to the outside of scheduler.” at our end. By default, our Scheduler appointment is only draggable inside the Scheduler content area. Dragging appointment is enabled through the eventDragArea property of the Schedule. If you using eventDragArea property you can disable the appointment dragging outside of the Schedule by removing the eventDragArea property. For the same, we have prepared a sample which can be available from the below link.
Kindly try the above sample and if we misunderstood your requirement kindly share more details with images or video demo that illustrates your requirement to serve you better.
Regards,
Ravikumar Venkatesan