Get data from a Firebase Realtime Database child - firebase

Question

This my project I have 2 RecyclewView, the first selects the user I want to manipulate, which is working perfectly.
When selecting it I store your id and transfer it to a next screen that should show your medical history (using your id to search your database for your history).
But this recycler view remains blank, does not give an error but also does not return anything, maybe I'm missing the time to put the path to be taken to bring this history.
image BD Firestore: [1]: https://imgur.com/HOxQTsI
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_verificar_historico)
setSupportActionBar(toolbar_historico)
toolbar_historico.setTitle("Titulo Aqui")
userId = intent.extras?.getString("userId")
textViewX.setText(userId)
getLastKey()
val layoutManager = LinearLayoutManager(this)
recycler_view_historico.layoutManager = layoutManager
val dividerItemDecoration = DividerItemDecoration(recycler_view_historico.context, layoutManager.orientation)
recycler_view_historico.addItemDecoration(dividerItemDecoration)
adapter = HistoricoAdapter(this)
recycler_view_historico.adapter = adapter
getHistorico()
recycler_view_historico.addOnScrollListener(object : RecyclerView.OnScrollListener() {
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
super.onScrolled(recyclerView, dx, dy)
total_item = layoutManager.itemCount
last_visible_item = layoutManager.findLastVisibleItemPosition()
if (isLoading && total_item <= last_visible_item + ITEM_COUNT) {
getHistorico()
isLoading = true
}
}
})
}
private fun getHistorico() {
if (!isMaxData) {
val query: Query
if (TextUtils.isEmpty(last_node))
query = FirebaseDatabase.getInstance().reference
.child("pacientes/$userId/historico")
.orderByKey()
.limitToFirst(ITEM_COUNT)
else
query = FirebaseDatabase.getInstance().reference
.child("pacientes/$userId/historico")
.orderByKey()
.startAt(last_node)
.limitToFirst(ITEM_COUNT)
query.addListenerForSingleValueEvent(object : ValueEventListener {
override fun onCancelled(p0: DatabaseError) {
}
override fun onDataChange(p0: DataSnapshot) {
if (p0.hasChildren()) {
val historicoLista = ArrayList<HistoricoRecycle>()
for (snapshot in p0.children)
historicoLista.add(snapshot.getValue(HistoricoRecycle::class.java)!!)
last_node = historicoLista[historicoLista.size - 1].data
if (!last_node.equals(last_key))
historicoLista.removeAt(historicoLista.size - 1)
else
last_node = "end"
adapter.addAll(historicoLista)
isLoading = false
} else {
isLoading = false
isMaxData = true
}
}
})
}
}
private fun getLastKey() {
val get_last_key = FirebaseDatabase.getInstance().getReference()
.child("pacientes/$userId/historico")
.orderByKey()
.limitToLast(1)
get_last_key.addListenerForSingleValueEvent(object : ValueEventListener {
override fun onCancelled(p0: DatabaseError) {
}
override fun onDataChange(p0: DataSnapshot) {
for (userSnapShot in p0.children)
last_key = userSnapShot.key
}
})
}