Mvvmcross 6.2.3 strange behavior of viewmodel navigation - mvvmcross

Question

I'm playing with MVVMCROSS 6.2.3 and I have an issue with nested navigation in my XForms UWP app.
Here is a description:
VM1 navigate to VM2 and VM1 is waiting for a result of VM2!
VM2 navigate to VM3, VM2 does not need a result of VM3.
After navigation from VM2 to VM3 and VM1 is unexpectedly getting a null result.
public class MainViewModel : MvxViewModel
{
public IMvxAsyncCommand GoToSecondPageCommand =>
new MvxAsyncCommand(async () =>
{
var param = new Dictionary<string, string> { { "ButtonText", ButtonText } };
var result = await navigationService.Navigate<SecondViewModel, Dictionary<string, string>, SecondViewModelResult>(param);
var breakpoint = 1;
//HERE IS THE ISSUE, result IS NULL because it fires immediately after Navigate<ThirdViewModel>()
});
public IMvxAsyncCommand BackCommand => new MvxAsyncCommand(async () =>
{
await navigationService.Close(this, new SecondViewModelResult { Result = "Back button clicked" });
});
}
public class SecondViewModel : MvxViewModel<Dictionary<string, string>, SecondViewModelResult>
{
public IMvxAsyncCommand GoToThirdPageCommand =>
new MvxAsyncCommand(async () =>
{
var t = await navigationService.Navigate<ThirdViewModel>();
var breakpoint = 2;
});
}
public class ThirdViewModel : MvxViewModel
{
}
You could run it by yourself from my GitHub https://github.com/JTOne123/XamFormsMvxTemplate
This behavior was good in version 5.7 and VM1 is waiting until VM2 return the result.
What am I doing wrong?