SwiftUI Tutorial - the case of the missing row

I'm working through the Handling User Input tutorial, which I am assuming many of you have done as well.


If I preview LandmarkList immediately after Section 2, Step 3 with showFavoritesOnly set to true, I get a blank cell when showFavoritesOnly is set to true.


After completing Section 3, Step 1 -- with the iteration through landmarkData being driven by the ForEach, this problem resolves itself -- the blank cell is no longer visible when showFavoritesOnly is set to true.


Can someone please explain why this extra blank cell is showing up?