This code does not work, meaning onChange is never called and the variable is not changed when a dropdown option is selected.

struct ExamplePicker: View {
    
    @State var val: Int32 = 2
    
    var body: some View {
        HStack {
            
            Menu {
                
                Picker(selection: $val, label: EmptyView()) {
                    
                    Text("Val1").tag(1)
                    Text("Val2").tag(2)
                    Text("Val3").tag(3)
                }
                
                
            } label: {
                HStack {
                    Text("Value: ")
                    Spacer()
                    
                    Text(String(format: "%d", val))
                    
                    Spacer()
                }
                
            }
            .onChange(of: val) { newSelection in
               print(">>> HERE")
           }
            
            
        }
        
    }
}

but if you change val to type Int it works perfectly fine. Int64 also works with no problem.
This looks like a bug to me

>Solution :

It works fine when the tag values of the Picker items have the same type as the state variable. Like this:

Picker(selection: $val, label: EmptyView()) {
    Text("Val1").tag(Int32(1))
    Text("Val2").tag(Int32(2))
    Text("Val3").tag(Int32(3))
}