File contents not showing?

Question

C++ / C#

Here is the code that should:
1. Open the file and read its contents
2. Write the contents to a variable, the value of which is then assigned to the variable in the ViewModel and associated with the View

The code

public static async void OpenNewFile()
        {
            FileOpenPicker openFilePicker = new FileOpenPicker();
            openFilePicker.ViewMode = PickerViewMode.Thumbnail;
            openFilePicker.FileTypeFilter.Add(".txt");

            var file = await openFilePicker.PickSingleFileAsync();

            if(file != null)
            {
                OpenedFileContent = await FileIO.ReadTextAsync(file);
            }
        }

In the debugger I see that the variable

OpenedFileContent

no value is assigned and equals it

null

.
I would be very grateful for any answer that will help