firebase-kotlin-sdk: suspending function firestore#collection#add hangs

Every now and then - maybe about 10% of the times - the following code just hangs:

override fun createTask(title: String, callback: (SuccessFailure<Unit>) -> Unit) = MainScope().launch {
  try {
    val task = FireStoreTodoTask(
        title = title
    )

    val path = "${list.path}/tasks"
    logI(TAG, "On $path creating task $task")
    firebaseStore.collection(path).add(task, FireStoreTodoTask.serializer())
    logI(TAG, "Creating task succeeded")
    callback.invoke(Success(Unit))
  } catch (throwable: Throwable) {
    logI(TAG, "Creating task failed", throwable)
    callback.invoke(Failure(TAG, throwableReasonConverter.convert(throwable)))
  }
}

After firebaseStore.collection(path).add(task, FireStoreTodoTask.serializer()) nothing happens. The suspend function just keeps running. Neither end I up in the next line nor I get thrown at.

Has anyone else been experiencing this?