I m having trouble understanding how SaveState and the BackS kotlinlang #compose

I'm having trouble understanding how SaveState and the BackStack work with the navigation-compose library. In my app I have a route with an argument such as

user/{userId}

. However, when I use

restoreState=true

in the NavOptionsBuilder, I can only navigate to a given userId once, then all further navigations land at the same userId destination. Setting

restoreState=false

fixes this issue, though I miss out on restoring the state of the viewmodel and composables from the previous time the destination was visited. How do I ensure the route argument is considered in the saveState used by navigation compose?

Copy code

NavHost(
        navController = navController,
    ) {
        composable(route = "users) {
            UsersScreen(onSelectUser = {userId -> navController.navigateSingleTopTo("user/$userId")})
        }
        composable(
            route = "user/{userId}",
            arguments = listOf(navArgument("userId") { type = NavType.IntType })
        ) {backStackEntry ->
            UserDetailScreen(
                onBackNav = { navController.navigateSingleTopTo("users")}
            )
        }
    }

And I'm using the nav function recommended by the android docs -

Copy code

fun NavHostController.navigateSingleTopTo(route: String) =
    this.navigate(route) {
        // Pop up to the start destination of the graph to
        // avoid building up a large stack of destinations
        // on the back stack as users select items
        popUpTo(
            this@navigateSingleTopTo.graph.findStartDestination().id
        ) {
            saveState = true
        }
        // Avoid multiple copies of the same destination when
        // reselecting the same item
        launchSingleTop = true
        // Restore state when reselecting a previously selected item
        restoreState = true
    }