On further investigation I find that producing the list in either of the following ways works. I still do not understand why the version I used doesn't. I think it should.

   // this works
   Group {
      List(viewModel.lineup) { PlayerRowView(player: $0) }
   }

   // so does this
   ScrollView {
      List(viewModel.lineup) { PlayerRowView(player: $0) }
   }