FragmentScenario doesn't work as expected

I'm using almost the as same architecture as Google sample: GithubBrowserSample.

This field is injected in my Fragment class:

@Inject
lateinit var viewModelFactory: ViewModelProvider.Factory

In all my fragments tests I got this error which corresponds to a field that is instantiated by injection:

java.lang.RuntimeException: kotlin.UninitializedPropertyAccessException: lateinit property viewModelFactory has not been initialized

This happens when I set my fragment like this with FragmentScenario:

viewModel = mock(TrainingListViewModel::class.java)

val scenario = launchFragmentInContainer(themeResId = R.style.Theme_LafayWorkbook) {
    TrainingListFragment().apply {
        appExecutors = countingAppExecutors.appExecutors
        viewModelFactory = ViewModelUtil.createFor(viewModel)
    }
}

dataBindingIdlingResourceRule.monitorFragment(scenario)
scenario.onFragment { fragment ->
    Navigation.setViewNavController(fragment.requireView(), navController)
    fragment.binding.trainingListRv.itemAnimator = null
    fragment.disableProgressBarAnimations()
}

But when I setup the Fragment before using it with FragmentScenario it works:

viewModel = mock(TrainingListViewModel::class.java)
val trainingListFragment = TrainingListFragment()
trainingListFragment.viewModelFactory = ViewModelUtil.createFor(viewModel)
trainingListFragment.appExecutors = countingAppExecutors.appExecutors

trainingListFragment.viewLifecycleOwnerLiveData.observeForever { viewLifecycleOwner ->
    if (viewLifecycleOwner != null) {
        Navigation.setViewNavController(trainingListFragment.requireView(), navController)
    }
}

val scenario = launchFragmentInContainer(themeResId = R.style.Theme_LafayWorkbook) {
    trainingListFragment
}

Here is the source code of my test:

@RunWith(AndroidJUnit4::class)
class TrainingListFragmentTest {
    @Rule
    @JvmField
    val executorRule = TaskExecutorWithIdlingResourceRule()

    @Rule
    @JvmField
    val countingAppExecutors = CountingAppExecutorsRule()

    @Rule
    @JvmField
    val dataBindingIdlingResourceRule = DataBindingIdlingResourceRule()

    private val navController = mock<NavController>()
    private val trainingsLiveData = MutableLiveData<Resource<List<Training>>>()
    private val isPremiumLiveData = MutableLiveData<PremiumAccount>()
    private val trainingDeletedLiveData = MutableLiveData<Event<Boolean>>()
    private val navigateToCreateTrainingLiveData = MutableLiveData<Event<Boolean>>()
    private val navigateToExerciseListLiveData = MutableLiveData<Event<Training>>()
    private lateinit var viewModel: TrainingListViewModel

    @Before
    fun init() {
        viewModel = mock(TrainingListViewModel::class.java)
        val trainingListFragment = TrainingListFragment()
        trainingListFragment.viewModelFactory = ViewModelUtil.createFor(viewModel)
        trainingListFragment.appExecutors = countingAppExecutors.appExecutors

        trainingListFragment.viewLifecycleOwnerLiveData.observeForever { viewLifecycleOwner ->
            if (viewLifecycleOwner != null) {
                Navigation.setViewNavController(trainingListFragment.requireView(), navController)
            }
        }

        `when`(viewModel.trainingsLiveData).thenReturn(trainingsLiveData)
        `when`(viewModel.isPremium).thenReturn(isPremiumLiveData)
        `when`(viewModel.trainingDeleted).thenReturn(trainingDeletedLiveData)
        `when`(viewModel.navigateToCreateTraining).thenReturn(navigateToCreateTrainingLiveData)
        `when`(viewModel.navigateToExerciseList).thenReturn(navigateToExerciseListLiveData)

        val scenario = launchFragmentInContainer(themeResId = R.style.Theme_LafayWorkbook) {
            trainingListFragment
        }
        dataBindingIdlingResourceRule.monitorFragment(scenario)
        scenario.onFragment { fragment ->
            Navigation.setViewNavController(fragment.requireView(), navController)
            fragment.binding.trainingListRv.itemAnimator = null
            fragment.disableProgressBarAnimations()
        }
    }

}

Do you guys have an idea about why this is happening and how I can fix it? I'm really struggling on this :(