Exceptions are just ignored in async code block

Before I use Nito.MVVM, I used plain async/await and it was throwing me an aggregate exception and I could read into it and know what I have. But since Nito, my exceptions are ignored and the program jumps from async code block and continue executes. I know that it catch exceptions because when I put a breakpoint on catch(Exception ex) line it breaks here but with ex = null. I know that NotifyTask has properties to check if an exception was thrown but where I put it, it checks when Task is uncompleted, not when I need it.

View model:

public FileExplorerPageViewModel(INavigationService navigationService)        {            _navigationService = navigationService;            _manager = new FileExplorerManager();            Files = NotifyTask.Create(GetFilesAsync("UniorDev", "GitRemote/GitRemote"));        }

Private method:

private async Task<ObservableCollection<FileExplorerModel>> GetFilesAsync(string login, string reposName)        {            return new ObservableCollection<FileExplorerModel>(await _manager.GetFilesAsync(login, reposName));        }

Manager method(where exception throws):

 public async Task<List<FileExplorerModel>> GetFilesAsync(string login, string reposName)        {            //try            //{                var gitHubFiles = await GetGitHubFilesAsync(login, reposName);                var gitRemoteFiles = new List<FileExplorerModel>();                foreach ( var file in gitHubFiles )                {                    if ( file.Type == ContentType.Symlink || file.Type == ContentType.Submodule ) continue;                    var model = new FileExplorerModel                    {                        Name = file.Name,                        FileType = file.Type.ToString()                    };                    if ( model.IsFolder )                    {                        var nextFiles = await GetGitHubFilesAsync(login, reposName);                        var count = nextFiles.Count;                    }                    model.FileSize = file.Size.ToString();                    gitRemoteFiles.Add(model);                }                return gitRemoteFiles;            //}            //catch ( WebException ex )            //{            //    throw new Exception("Something wrong with internet connection, try to On Internet "+ ex.Message);            //}            //catch ( Exception ex )            //{            //    throw new Exception("Getting ExplorerFiles from github failed! "+ ex.Message);            //}        }

With try/catch or without it has the same effect. This behavior is anywhere where I have NotifyTask.

UpdateThere is no event, that fires when exception occurred, but there is Property Changed event, so I used it and added this code:

private void FilesOnPropertyChanged(object sender, PropertyChangedEventArgs propertyChangedEventArgs)        {            throw new Exception("EXCEPTION");            bool failed;            if ( Files.IsFaulted )                failed = true;        } 

And exception not fires. I added throw exception in App class (main class) and it fired. And when I have exceptions that come from XAML, it also fires. So maybe it not fires when it comes from a view model, or something else. I have no idea. Will be very happy for some help with it.Update

We deal with exception = null, but the question is still alive. What I wanna add, that I rarely this issue, when the app is starting to launch on the physic device. I read some info about it, and it doesn't seem to be related, but maybe it is: