Hi anass,
Thank you for contacting Syncfusion support.
We have prepared a sample based on the requirement and it works as expected without any issues, which can be downloaded from the below link.
Kindly let us know whether the provided sample fulfils your requirement. If not Kindly modify the sample or Xaml files to reproduce the issue and share us the same which will be helpful for us to provide you a prompt solution at the earliest.
Regards,
Devaraj S