B4R Question MQTT port 1883 blocked on mobile networks (4G/)? Is this expected and what is the best workaround?

Private MQTT As MqttClient
    Private MQTTUser As String = "teste"
    Private MQTTPassword As String = "00000000"
    Private MQTTServerURI As String = "tcp://broker.hivemq.com:1883"'change for other broker

'You can see the list of page related events in the B4XPagesManager object. The event name is B4XPage.
'Connect to CloudMQTT broker
Sub MQTT_Connect
    MQTT_Nome=Nome_Text3.Text
    MQTT_Senha=Senha_Text4.Text
    MQTT_Url=Url_Text1.Text
    MQTT_Port=Port_Text2.Text
    Dim ClientId As String = Rnd(0, 999999999) 'create a unique id
    MQTT. Initialize("mqtt",MQTT_Url & ":" & MQTT_Port , ClientId)
    Dim ConnOpt As MqttConnectOptions
    ConnOpt.Initialize(MQTT_Nome,MQTT_Senha)
    MQTT.Connect2(ConnOpt)
End Sub

'MQTT CONNECT AND SUBSCRIBE TO TOPIC
Sub MQTT_Connected (Success As Boolean)
    If Success = False Then
        Log(LastException)
        xui.MsgboxAsync("Error de Conexão","")
    Else
        Conectar.Text = "Conectado"
        Conectar.TextColor = xui.Color_Red
        MQTT.Subscribe("Control_Rele8/#", 1)'change the name of the topic!
        MQTT.Subscribe("Relay_0",1)'change the name of the topic!
        MQTT.Subscribe("Relay_1",1)'change the name of the topic!
        MQTT.Subscribe("Relay_2",1)'change the name of the topic!
        MQTT.Subscribe("Relay_3",1)'change the name of the topic!
        MQTT.Subscribe("Relay_4",1)'change the name of the topic!
        MQTT.Subscribe("Relay_5",1)'change the name of the topic!
        MQTT.Subscribe("Relay_6",1)'change the name of the topic!
        MQTT.Subscribe("Relay_7",1)'change the name of the topic!
        MQTT.Subscribe("Relay_8",1)'change the name of the topic!
        MQTT.Subscribe("Temp_Ds",1)'<--- ADD
    End If
End Sub

Private Sub Conectar_Click
    If Conectar.Text = "Conectado" Then
        xui.MsgboxAsync("Você está Conectado!","Casa Controle 1")
    Else
        MQTT_Connect
    End If
End Sub


Sub mqtt_MessageArrived(Topic As String, payload()As Byte)
    If Conectar.Text = "Conectado" Then
    Temp = BytesToString(payload,0,payload.Length,"UTF-8")
        If Topic = "Temp_Ds" Then
            Label4.Text = Temp & " °C"
    End If
    End If
    End Sub
    


Private Sub Desconectar_Click
    If MQTT.IsInitialized Then
        MQTT.Close
    End If
    ExitApplication
End Sub