MutableLiveData.postValue isn't recomposing my view

Multiplatform
1

I am trying to get some data from a webservice that I only need to call once per start of my app, as the data is updated so seldom.

My view model is the core of this section.

val courseList = MutableLiveData<CourseCatalog>()

    init {
        viewModelScope.launch {
            val courses = ecRepository.fetchCourses { it -> courseList.postValue(it) }
            logger.i { "Number of courses returned is ${courseList.value?.courses?.size}" }
        }
    }

It calls my repository and this does work, and the ViewModel logger also prints the number of courses returned.

    suspend fun fetchCourses(courseListNavigation: (courseList:CourseCatalog) -> Unit)  {
        logger.d { "fetchAndStoreCourses" }
        courseList = CourseCatalog(ecApi.fetchCourseCatalog().toList())
        courseListNavigation(courseList!!)
    }

But here my view never gets to items=it1.courses and so never gets to CourseView

    val ecViewModel = getViewModel<ECViewModel>()
    val courseListState = ecViewModel.courseList

    Scaffold(
        topBar = {
            TopAppBar(title = { Text("People In Space") })
        }) {
        LazyColumn(contentPadding = paddingValues) {
            courseListState.value?.let { it1 ->
                items(
                    items = it1.courses
                ) { person ->
                    CourseView(person, personSelected)
                }
            }
        }
    }

Why am I not having the mutablelivedata.postvalue not sending a message to courseListState so the view can be recomposed?

I am using Kotlin 1.4.32 and jetpack compose 1.0.0-beta06.