Winforms app still crashes after unhandled exception handler

I've applied these handlers in a test application:

    Application.ThreadException += Application_ThreadException;
    Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException);
    AppDomain.CurrentDomain.UnhandledException += CurrentDomain_UnhandledException;
    TaskScheduler.UnobservedTaskException += TaskScheduler_UnobservedTaskException;

I then create an exception on a nested Task/Async await on the form:

Despite the handler being fired - CurrentDomain.UnhandledException - the app still crashes.

System.Exception was unhandled Message: An unhandled exception of type 'System.Exception' occurred in mscorlib.dll Additional information: dd

private async void button1_Click(object sender, EventArgs e)
{
    Console.WriteLine("Main " + Thread.CurrentThread.ManagedThreadId);
    try
    {
        await Hello();
    }
    catch (Exception ex)
    {
        Console.WriteLine("Exception on main  " + Thread.CurrentThread.ManagedThreadId);
    }
}

private async static Task Hello() //changed from void
{
    await Task.Run(() => new IGetRun().Run1());
}

internal class IGetRun
{
    public async Task Run1() //changed from void
    {
        Console.WriteLine("Run1 " + Thread.CurrentThread.ManagedThreadId);
            await Task.Run(() => new IGetRun2().Run2());
    }
}

internal class IGetRun2
{
    public void Run2()
    {
        Console.WriteLine("Run2 " + Thread.CurrentThread.ManagedThreadId);
        throw new Exception("dd");
    }
}

EDIT: Looks like I forgot to declare each async method with Task and not void thus exception handling works predictably now. The only thing I still do not know is why - if I stop handling the exception in the button event - when the exception is caught Application_ThreadException is fired and not TaskScheduler_UnobservedTaskException