osmdroid map disappears after switchings tabs

Question

I want to show a map using OSMdroid. I have a singleton to create the MapView:

object MapViewSingleton {
    private var mapView: MapView? = null

    fun getMapView(context: Context): MapView {
        if (mapView == null) {
            mapView = createMapView(context)
        }
        return mapView!!
    }

    private fun createMapView(context: Context): MapView {
        if (mapView != null) {
            if (mapView!!.parent != null) {
                (mapView!!.parent as ViewGroup).removeView(mapView)
            }
        }
        val mapView = MapView(context)

        Configuration.getInstance().load(context, PreferenceManager.getDefaultSharedPreferences(context))
        Configuration.getInstance().userAgentValue = "Test"

        mapView.setTileSource(TileSourceFactory.MAPNIK)
        mapView.setMultiTouchControls(true)

        return mapView
    }
}

I use this composable function to show the map:

@Composable
fun OsmdroidMapView() {
    val mapView = MapViewSingleton.getMapView(LocalContext.current)
    AndroidView(
        modifier = Modifier.fillMaxSize(),
        factory = {
            mapView
        }
    )
}

The map is shown on the display when its the first time i go on the map tab. When i switch to another tab and come back the map tab, the map disappeared. I can now see only an empty grid.

This is the way I implemented the tabs:

val items = listOf(
                BottomNavigationItem(
                    route = "settings",
                    title = "Einstellungen",
                    selectedIcon = Icons.Filled.Settings,
                    unselectedIcon = Icons.Outlined.Settings
                ),
                BottomNavigationItem(
                    route = "map",
                    title = "Karte",
                    selectedIcon = Icons.Filled.Place,
                    unselectedIcon = Icons.Outlined.Place
                ),
                BottomNavigationItem(
                    route = "data",
                    title = "Daten",
                    selectedIcon = Icons.Filled.Done,
                    unselectedIcon = Icons.Outlined.Done
                )
            )

            var selectedItemIndex by rememberSaveable { mutableStateOf(0) }
            val navController = rememberNavController()
            Scaffold(
                bottomBar = {
                    NavigationBar {
                        items.forEachIndexed { index, item ->
                            NavigationBarItem(
                                selected = selectedItemIndex == index,
                                onClick = {
                                    selectedItemIndex = index
                                    navController.navigate(item.route)
                                },
                                label = {
                                    Text(text = item.title)
                                },
                                icon = {
                                    BadgedBox(badge = {}) {
                                        Icon(
                                            imageVector = if (index == selectedItemIndex) {
                                                item.selectedIcon
                                            } else item.unselectedIcon,
                                            contentDescription = item.title
                                        )
                                    }
                                }
                            )
                        }
                    }
                }
            ) {
                NavHost(navController = navController, startDestination = "settings") {
                    composable("map") {
                        OsmdroidMapView()
                    }
                    composable("settings") {
                        Settings()
                    }
                    composable("data") {
                        Data()
                    }
                }
            }

Can anyone see the mistake I did and tell me why i can only see an empty grid after switching tabs?