Hi Claudio,
We have checked the SfCalendar behavior in both UWP and WinRT platform. In this the calendar SelectionChanged event gets triggered while changing the the month view. We have prepared a workaround sample in this sample we have maintained the boolean variable named IsnavigationButtonpressed to check the event is triggered by changing month view or change the selected date.
Please download the sample from the below link.
Sample link:
SfCalendar_UWP
Please let us know if you need further assistance.
Regards,
Mariappan S.