Data-driven WindowGroup opens window when the application starts

When writing a menu-bar application using MenuBarExtra, I want to open a new window when the user taps on a button. I am using .openWindow and data-driven WindowGroup for that purpose.

The issue is that the WindowGroup window also opens when the application starts. I would expect the WindowGroup window not to open when the application starts.

Here's a minimal example that reproduces the issue:

import SwiftUI

@main
struct TestApp: App {
    @Environment(\.openWindow) var openWidow

    var body: some Scene {
        MenuBarExtra(isInserted: .constant(true)) {
            Button("Open window") {
                openWidow(value: "Hello 👋")
            }
        } label: {
            Text("Test App")
        }

        WindowGroup("Test", for: String.self) { $str in
            if let str {
                Text(str)
            }
        }
    }
}

There is a workaround using an application delegate:

class AppDelegate: NSObject, NSApplicationDelegate {
    func applicationDidFinishLaunching(_ notification: Notification) {
        if let window = NSApplication.shared.windows.first(where: { $0.title == "Test" }) {
            window.close()
        }
    }
}

Am I missing anything?