When using List as State, how to update UI when item`attribute change in Jetpack Compose?

For example, I load data into a List, it`s wrapped by MutableStateFlow, and I collect these as State in UI Component.

The trouble is, when I change an item in the MutableStateFlow<List>, such as modifying attribute, but don`t add or delete, the UI will not change.

So how can I change the UI when I modify an item of the MutableStateFlow?

These are codes:

ViewModel:

data class TestBean(val id: Int, var name: String)
class VM: ViewModel() {
    val testList = MutableStateFlow<List<TestBean>>(emptyList())

    fun createTestData() {
        val result = mutableListOf<TestBean>()
        (0 .. 10).forEach {
            result.add(TestBean(it, it.toString()))
        }
        testList.value = result
    }

    fun changeTestData(index: Int) {

        // first way to change data
        testList.value[index].name = System.currentTimeMillis().toString()

        // second way to change data
        val p = testList.value[index]
        p.name = System.currentTimeMillis().toString()
        val tmplist = testList.value.toMutableList()
        tmplist[index].name = p.name
        testList.update { tmplist }
}

}

UI:

    setContent {
        LaunchedEffect(key1 = Unit) {
            vm.createTestData()
        }
        Column {
            vm.testList.collectAsState().value.forEachIndexed { index, it ->
                Text(text = it.name, modifier = Modifier.padding(16.dp).clickable {
                    vm.changeTestData(index)
                    Log.d("TAG", "click： ${index}")
                })
            }
        }
    }