iOS 26: Navigation bar unexpectedly switches to Light appearance during navigation in Dark Mode

Summary

On iOS 26, the navigation bar unexpectedly switches to a Light appearance during/after a view transition while the device/app is in Dark Mode. This seems correlated with applying listStyle(.plain) to a List. Removing .plain prevents the issue, but my app’s layout requires it.

Sample code:

import SwiftUI

@main
struct iOS26NavigationTitleSampleApp: App {
    var body: some Scene {
        WindowGroup {
            NavigationStack {
                ContentView()
                    .navigationTitle("Root")
                    .navigationBarTitleDisplayMode(.inline)
            }
        }
    }
}

struct ContentView: View {
    var body: some View {
        VStack {
            NavigationLink {
                ListView()
            } label: {
                VStack {
                    Image(systemName: "globe")
                        .imageScale(.large)
                        .foregroundStyle(.tint)
                    Text("Hello, world!")
                }
            }
        }
        .padding()
        .toolbar {
            ToolbarItemGroup(placement: .navigation) {
                Button("Test") {
                }
                Button("Test2") {
                }
            }
        }
    }
}

struct ListView: View {
    
    var items: [Int] = Array(0..<100)
    
    var body: some View {
        List {
            ForEach(items.indices, id: \.self) { idx in
                cell(items[idx])
            }
        }
        .listStyle(.plain)
        .toolbar {
            ToolbarItemGroup(placement: .navigation) {
                Button("Test") {
                }
                Button("Test2") {
                }
            }
            
        }
        .navigationTitle("TTT")
    }
    
    private func cell(_ item: Int) -> some View {
        Text("\(item)")
    }   
}

Steps to Reproduce:

1. Set the device to Dark Mode.
2. Launch the sample app. → The root view’s navigation bar is in Dark appearance (as expected).
3. Tap “Hello World” to navigate. → On the destination view, the navigation bar becomes Light.
4. Navigate back to the root view. → The root view’s navigation bar now also remains Light.

Expected Result

The navigation bar should consistently retain the Dark appearance throughout navigation.

Notes

• Removing listStyle(.plain) stops the issue (navigation bar stays Dark).
• Simulator: Could not reproduce on iOS Simulator.
• Devices: Reproducible on physical device.

Environment

• Device: iPhone 15 Plus
• OS: iOS 26 (23A341)
• Xcode: 26.0 (17A324)