Thank you for contacting Syncfusion support.
We have checked with our latest Essential Studio Volume 3 SP1, 2017 (Version 220.127.116.11) and we are unable to reproduce the mentioned issue with Schedule AppointmentCollection not clearing in the UI in Xamarin Forms from our side. We have prepared sample for the same, please find the below sample.
Could you please confirm whether you’re using this same version and if you face any issue please revert us by modifying the provided sample based on your requirement. It will be helpful for us to check on it and provide you the solution.
Subburaj Pandian V.