microsoft-authentication-library-for-dotnet: [Bug] Log-in window is sometimes left running by itself/orphaned

I’m experimenting with WinappSDK / WinUI3. Coming from UWP, one odd thing I’ve noticed is sometimes when my app closes/crashes, the MSAL sign-in window is left running on its own/orphaned. Why does that happen and is there a way to prevent it?

Which version of MSAL.NET are you using? 4.49.1-preview

Platform WinappSDK 1.3 expermintal1, WinUI3

** Repro ** It repros fine with a console app.

    static async Task Main(string[] args)
    {
            var pca = PublicClientApplicationBuilder
                .Create("4b0db8c2-9f26-4417-8bde-3f0e3656f8e0")
                .WithRedirectUri("http://localhost")
                .WithBrokerPreview(true)
                .Build();

            var result = pca.AcquireTokenInteractive(new[] { "user.read" })
                .WithParentActivityOrWindow(GetConsoleOrTerminalWindow())
                .ExecuteAsync();
           
            // WAM account picker pops up here.
            await Task.Delay(1000);

            // app crashes, but instead of closing, both console and Account picker remain on the screen. Console is modal.
            throw new Exception("oh no");
    }

Actual: when app crashes, the account picker stays on screen and so does the console window, which remains modal. Account Picker seems to be blocking the window from closing after the crash. App appears “frozen”

Expected: on app crash, Account picker and app should close.