Alert not continuously showing on iOS 18b2

ContentView.swift

import SwiftUI

struct ContentView: View {
    struct AlertConfig: AlertPresentable {
        var isPresented: Bool = false {
            didSet {
                if !isPresented {
                    dismissAction?()
                    dismissAction = nil
                }
            }
        }

        var dismissAction: (() -> Void)? = nil
        mutating func present(dismissAction: @escaping () -> Void) {
            self.dismissAction = dismissAction
            self.isPresented = true
        }
    }
    
    @State private var config = AlertConfig()
    
    var isPresented: Binding<Bool> {
        get {
            Binding {
                config.isPresented
            } set: { b in
                config.isPresented = b
            }
        }
    }
    
    var body: some View {
        Text("Hello world!")
            .alert("Hi", isPresented: $config.isPresented) { // works on 17.5, on 18b2 it only appears once.
//          .alert("Hi", isPresented: isPresented) { // works on 17.5 and 18b2.
              // rely on default button
            }
            .task {
                while(!Task.isCancelled) {
                    await withCheckedContinuation { continuation in
                        config.present {
                            continuation.resume()
                        }
                    }
                }
            }
    }
    
}