android: no view found for id for fragment

Question

I'm sorry for posting a question on the subject again but this is driving me crazy.

I have a fragment and I'm adding views programmatically to a LinearLayout:

<LinearLayout
                    android:id="@+id/items_container"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:orientation="vertical"/>

val items =buildView1(event) +buildView2(event) +buildCrew(event) 
items.forEach {dataBinding.itemsContainer.addView(it)}

crew is a fragments, so I add it like this:

private fun buildCrew(event: Event): List<View> {
        return listOf(
            FrameLayout(requireContext()).apply {
                id = View.generateViewId()
                val transaction = childFragmentManager.beginTransaction()
                val f = CrewFragment()
                transaction.add(id, f)
                transaction.commit()
        })
    }

it works but navigating away from this page and coming back results in the error:

No view found for id 0x1 (unknown) for fragment CrewFragment{92ba272}

I also tried to create a custom view with a FragmentContainerView:

<androidx.fragment.app.FragmentContainerView
        android:id="@+id/event_detail_crew"
        android:name="redacted.package.CrewFragment"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

this solves the error but causes two problems:

• the fragment seemed to be attached using the activity's fragment manager, I need the containing fragment's childFragmentManager as the two need to share a viewModel with

  private val viewModel: CrewViewModel by lazy { requireParentFragment().getViewModel() }

• when navigating away and coming back the contents of CrewFragment are not visible anymore, none of CrewFragment's lifecycle methods are called

What is going on here?