问如何在reloadWithDebugInfo之后获取Angularjs作用域变量？

EN

    private Page _page;
    private Browser _browser;

    private async void button1_ClickAsync(object sender, EventArgs e)
    {
        try
        {
            await initAsync();
            await test2Async();
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error : " + ex.Message);
        }
    }

    private async Task initAsync()
    {
        _browser = await Puppeteer.LaunchAsync(new LaunchOptions
        {
            Headless = false,
            ExecutablePath = @"c:\Program Files (x86)\Google\Chrome\Application\chrome.exe",
            Timeout = 60000
        });
    }

    private async Task test2Async()
    {
        try
        {
            _page = await _browser.NewPageAsync();

            await _page.GoToAsync("https://SOME Angular JS WebPage");

            await _page.EvaluateFunctionAsync(@"() => angular.reloadWithDebugInfo()");

            var scopeContent = await _page.EvaluateFunctionAsync("() => angular.element(document.getElementsByClassName('left-column-v3')).scope() ");

            // scopeContent is null. why? (the above javascript code runs successfully in the chrome dev console.)
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error : " + ex.Message);
        }
    }

        var scopeContent = await _page.EvaluateFunctionAsync("() => angular.element(document.getElementsByClassName('left-column-v3')).scope().SomeVariable ");