android compose 对象中属性改变界面不更新如何解决

compose中遇到一个问题，界面无法及时更新对象的属性值，只有当重新进入该界面该值才会改变。我从viewmodel中传到compose中的对象是BluetoothGattService，通过StateFlow更新，在我的界面列表里有BluetoothGattCharacteristic的value值的显示，当value值改变时，界面无法自动更新。关键代码如下：

class ScanViewModel @Inject constructor(
    private val bleManager: BLEManager,
    application: Application
) : AndroidViewModel(application) {
...
val discoveredServices: Flow<List<BluetoothGattService>> = bleManager.discoveredServicesFlow
...
}
@Composable
fun ScanScreen(
    navLogScreen: () -> Unit,
    viewModel: ScanViewModel = hiltViewModel()
) {
...
val discoveredServices by viewModel.discoveredServices.collectAsState(initial = listOf())
...
}

@Composable
fun ServiceCardListColumn(
    services: List<BluetoothGattService>,
) {
    LazyColumn() {
        services.forEach { service ->
            item {
                ServiceCard(service = service)
            }
        }
    }
}
@Composable
fun ServiceCard(
    service: BluetoothGattService,
) {
    Box(modifier = modifier) {
...
                Column {
                    service.characteristics.forEach {
                        ...
                            characteristicCard(
                                it,
                            )
                    }
                }
    }
}
@Composable
fun characteristicCard(
    characteristic: BluetoothGattCharacteristic,
) {
  ...
    Text(text = characteristic.value?.toHexString()?:"")
}