Push notification not reaching when app in foreground - codenameone

Question

I'm having trouble getting Push Notifications when the app is in foreground in an Android device. As soon as I put the app in the background all goes well.
This is the java code I use to send de notifications:
HttpClient client = HttpClientBuilder.create().build();
HttpPost httpPost = new HttpPost(URL_SERVER);
List<NameValuePair> arguments = new ArrayList<>();
arguments.add(new BasicNameValuePair("token", TOKEN));
arguments.add(new BasicNameValuePair("device", codigoApp));
arguments.add(new BasicNameValuePair("type", "1"));
arguments.add(new BasicNameValuePair("body", ip));
arguments.add(new BasicNameValuePair("auth", GOOGLE_AUTH));
try {
httpPost.setEntity(new UrlEncodedFormEntity(arguments));
HttpResponse response = client.execute(httpPost);
String result = EntityUtils.toString(response.getEntity());
System.out.println(result);
} catch (IOException ex) {
Logger.getLogger(NotificaReview.class.getName()).log(Level.SEVERE, null, ex);
}
And this is the code in the app:
public void start() {
if(current != null){
current.show();
return;
}
if (Push.getPushKey() != null)
devicePush = Push.getPushKey();
else
Display.getInstance().registerPush();
Form inicioGUI = new InicioGUI(devicePush);
inicioGUI.show();
}
public void stop() {
current = getCurrentForm();
if(current instanceof Dialog) {
((Dialog)current).dispose();
current = getCurrentForm();
}
}
public void destroy() {
}
#Override
public void push(String value) {
ToastBar.showMessage("Archivo recibido correctamente con IP" + value, FontImage.MATERIAL_INFO);
}
#Override
public void registeredForPush(String deviceId) {
devicePush = deviceId;
}
#Override
public void pushRegistrationError(String error, int errorCode) {
}
The ToastBar only shows when I bring the app to foreground after receiving the push while in background. The Push callback is never called if the app is alive.
Any ideas?

Answer 1

I need answers to my comment in the question which might help explain the issue. I'll edit this answer based on the updates to the question.
In the meantime I see several issues in the code. See my highlighted comments/fixes below:
public void start() {
if(current != null){
current.show();
return;
}
// don't check the push key, always register the device and
// always do it in a callSerially as it might trigger a prompt
callSerially(() -> registerPush());
Form inicioGUI = new InicioGUI(Push.getPushKey());
inicioGUI.show();
}
#Override
public void push(String value) {
ToastBar.showMessage("Archivo recibido correctamente con IP" + value, FontImage.MATERIAL_INFO);
}
#Override
public void registeredForPush(String deviceId) {
// deviceId is the native push key you need to use the actual
// push key value never device ID
devicePush = Push.getPushKey();
}
#Override
public void pushRegistrationError(String error, int errorCode) {
// you might have gotten a push error which might have explained the
// cause of the problem
Log.p("Push error " + errorCode + ":" + error);
Log.sendLogAsync();
}