Hi,
testing with latest V16.1.0.24 UWP (and the fix for the crash when Locale="de").
Problem: "DataSource" is connected to a property in ViewModel "ScheduleAppointments" via binding.
ScheduleAppointments are filled with new appointments via "VisibleDatesChangedCommand", but in "MonthView" not all appointments are shown.
"DayView" and "WeekView" seems to be fine.
I created a demo project with random appointments for every day to demonstrate the problem.
Regards, Siggi

Attachment:
ScheduleDemo_193b61f8.7z