Why did my NYS tax refund drop when I entered that I moved 3 days before the end of the year?

While preparing my fed return my refund for NYS/C was showing as well.  When I got to the NYS/C return, it asked me when I moved out of the state.  My answer triggered it to choose a non-resident form, but dropped by refund (even though I did not reduce any income I was paying state/local taxes on).