Button Glass Style Incorrect in Sheet + ScrollView on Mac Catalyst 26

Hi everyone!

I've encountered an issue when using Sheet + ScrollView on Mac Catalyst: the buttons in the toolbar appear with an abnormal gray color.

import SwiftUI

struct ContentView: View {
    var body: some View {
        VStack {
        }
        .sheet(isPresented: .constant(true)) {
            Sheet()
        }
    }
}

struct Sheet: View {
    var body: some View {
        NavigationStack {
            ScrollView { // <-- no issue if use List
            }
            .toolbar {
                Button(action: {}) { // <-- 👀 weird gray color
                    Image(systemName: "checkmark")
                }
            }
        }
    }
}

Steps to Reproduce:

1. On macOS 26.0 beta 9, use Xcode 26.0 beta 7 to create an iOS project and enable Mac Catalyst.
2. Paste the code above.
3. Select the Mac Catalyst scheme and run the project.
4. The buttons in the toolbar show a strange gray appearance.
5. If you change the ScrollView to a List in the code, the issue does not occur.

FB20120285