Anyone confused by the Integration with the bottom nav bar example for Navigation. Because of the nav options used, computing the current route as

navBackStackEntry?.arguments?.getString(KEY_ROUTE)

gives null when you go back to the start tab, so the nav item won't be highlighted. What works is

val backstackRoute = backstackEntry?.arguments?.getString(KEY_ROUTE)
val fallbackRoute = runCatching {
    nav.graph.findNode(nav.graph.startDestination)!!.arguments[KEY_ROUTE]!!.defaultValue
}.getOrNull()
val currentRoute = backstackRoute ?: fallbackRoute

(runCatching otherwise nav.graph can throw on first composition). What's wrong here? Do we need at least a better API for peeking the current route?