Why CefSharp.WinForms browser does not load when calling form with .Show instead of .ShowDialog?

I´m trying to open a ChildForm from my MainForm to show a web page with the library CefSharp, but it not load when using .Show function, but with .ShowDialog() it works.I need the ChildForm to be an independent form and not expect the user to close it to keep using the app.

Inside my ChildForm

// In the constructorthis.browser = new ChromiumWebBrowser(pdfUrl);this.browser.FrameLoadEnd += Browser_FrameLoadEnd;this.Controls.Add(browser);browser.Dock = DockStyle.Fill;private void Browser_FrameLoadEnd(object sender, FrameLoadEndEventArgs e){    // Some code ...}

The attatch event Browser_FrameLoadEnd does not execute, and the app crashes.