RecyclerView 不显示自定义视图

有问题RecyclerView，我在 Google 中找不到解决方案。里面有一个片段RecyclerView。元素被生成但不被渲染。

片段类 - https://github.com/LazyTechwork/QRScanner/blob/master/app/src/main/java/ru/lazytechwork/qrscanner/fragments/HistoryFragment.kt

class HistoryFragment : Fragment() {
    private var scans: List<Scan> = emptyList()
    private val ioScope = CoroutineScope(Dispatchers.IO)
    private lateinit var recyclerView: RecyclerView
    private lateinit var viewAdapter: ScanHistoryAdapter

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val view = inflater.inflate(R.layout.fragment_history, container, false)

        viewAdapter = ScanHistoryAdapter(scans, (activity as MainActivity).db)
        recyclerView = view.findViewById<RecyclerView>(R.id.scanlist).apply {
            setHasFixedSize(true)
            adapter = viewAdapter
        }

        ioScope.launch {
            scans = (activity as MainActivity).getScans()
            viewAdapter.updateDataset(scans)
        }
        return view
    }

}

片段 XML - https://github.com/LazyTechwork/QRScanner/blob/master/app/src/main/res/layout/fragment_history.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/scanlist"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:scrollbars="vertical"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
        app:layout_constrainedHeight="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        tools:listitem="@layout/history_item" />
</androidx.constraintlayout.widget.ConstraintLayout>

适配器代码 - https://github.com/LazyTechwork/QRScanner/blob/master/app/src/main/java/ru/lazytechwork/qrscanner/data/adapters/ScanHistoryAdapter.kt

class ScanHistoryAdapter(private var dataset: List<Scan>, private val db: AppDatabase) :
    RecyclerView.Adapter<ScanHistoryAdapter.ViewHolder>() {
    class ViewHolder(val historyItem: HistoryItem) : RecyclerView.ViewHolder(historyItem)

    override fun onCreateViewHolder(
        parent: ViewGroup,
        viewType: Int
    ): ViewHolder =
        ViewHolder(HistoryItem(parent, db))


    fun updateDataset(scans: List<Scan>) {
        dataset = scans
        notifyDataSetChanged()
    }

    override fun getItemCount(): Int = dataset.size

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        val viewItem = holder.historyItem
        val scan = dataset[position]
        viewItem.setScan(scan)
    }
}

在 Android Studio 中一切正常。