Greetings from Syncfusion support.
My opinion is that Cancel button does not works as should:
If there is already selected range in control, when user pickup new range and click cancel , I think that control should preserve old selected range, not new one.
What is point of cancel button if it still change value of range ?
the cancel button reset the current selection in the daterangepicker popup value not component value. So, in your case the components previous value will maintain the component object.
Is there an event for Apply button ?
We have validated your requirement with shared image. we do not have any event while clicking the apply button without previous selected value changed but we have triggered the ValueChange event after changed the value and clicking the apply button.