How to wait for all nested async functions to complete in Kotlin?

I have the following code in an Android mobile app. I need to make sure transaction.save() is always finished executing before dismiss() is called. Currently, it only works some of the time. I appreciate any advice on how to restructure this to run like I expect it to.

private fun save() {
   lifecycleScope.launch {
      showLoader()
      withContext(Dispatchers.IO) {
         transaction.save()
      }
      dismiss()
   }
}

Definition of transaction.save() method. onTripEvent is another suspend function that saves a record in the device database, and sends it to a web API. I won't bother providing its definition.

suspend fun save() {
   tripRepository.updateTripSourceItem(this)
   tripRepository.onTripEvent("Updated item etc.")
}

Definition of tripRepository.updateTripSourceItem

suspend fun updateTripSourceItem(tripSourceItem: TripSourceItem) {
   localDataSource.updateTripSourceItem(tripSourceItem)
   api.putTripSourceItem(tripSourceItem).await()
}

Definition of localDataSource.updateTripSourceItem

@Dao
interface TripDao {
   @Update
   suspend fun updateTripSourceItem(tripSourceItem: TripSourceItem)
}

Definition of api.putTripSourceItem

interface api {
   @POST("apiEndPoint")
   fun putTripSourceItem(
      @Body body: TripSourceItem
   ): Deferred<List<StatusResponse>>
}

I know it's best practice to use withContext(Dispatchers.IO) when accessing the database, but which function do I need that in? The top level save() function, transaction.save(), tripRepository.updateTripSourceItem(), or all of the above? I thought about putting something like this in every function, but it seems like overkill.

suspend fun save()
   withContext(Dispatchers.IO) {
         awaitAll(
             async { tripRepository.updateTripSourceItem(this@TripSourceItem) },
             async { tripRepository.onTripEvent("Updated item etc.") }
         )
      }
   }
}

You are using suspend in your updateTripSourceItem in your DAO.
When doing that, you are saying to Room "Make sure you do this at your own time, don't bother me or make me wait"

Since you want to wait until the database is properly updated, removing the suspend will do the trick and you won't need to do boilerplate code with awaits

Wrap the save call with async.

private fun save() {
    lifecycleScope.launch {
        showLoader()
        async(Dispatchers.IO) {
            transaction.save()
        }.await()
        dismiss()
    }