Ok I think I understood the issue because I have a lot of issues in this page which is not normal.
My page is in a tab. I use this code in my mainview
_pageService.CreatePage(typeof(ProfileView), null).ContinueWith((result) =>
{
profileView = result.Result as ProfileView;
profileTab.Content = profileView.Content;
});
But if I do this, I doubt it works with SfBackDropPage. For example the IsBackLayerRevealed is not working.
But if I set the content of the page it will ignore the properties of the page. I have also issues with scrollview in the backdroppage.
If I use all of this in a Page everything works.
So I think the question is more, how to setup a SfBackDropPage in a tabpage?