Open Modal

I have a ForEach listing a lot of eventos, having 1 image button for each of them.

When the button is clicked, I will open a modal with the selectedEvento.

The problem is even though I've the line "self.selectedEvento = evento" inside of the button actions, when I click the button for the first time, the selectedEvento is being passed as nil.

However if I click a second button, the process will happen succesfully.

Code:
...
@State var showModal = false
@State var selectedEvento: Evento!
...

ForEach(store.eventos) { evento in
          VStack() {
            Button(action: {
              self.selectedEvento = evento
              self.showModal.toggle()
               
            }) {
            WebImage(url: evento.thumbnail)
            }
          }
          .sheet(isPresented: $showModal) {
            if self.selectedEvento != nil {
              //open detailView
            } else {
              Text("Some Error State goes here")
            }
          }
        }

• ** Why is this happening ?

Shoudn't the first click also to be passing the selectedEvento ? Why it doesnt happen ?

Thx

Code Block 
struct MyView: View {
    //...
    
    var body: some View {
        //...
            .sheet(isPresented: $showModal) {
                MySheetView(selectedEvento: self.$selectedEvento)
            }
        //...
    }
}
struct MySheetView: View {
    @Binding var selectedEvento: Evento?
    
    var body: some View {
        if self.selectedEvento != nil {
            //open detailView
        } else {
            Text("Some Error State goes here")
        }
    }
}