Error getting firebase messaging token

I have an Android App that get the firebase messaging token with this code:

FirebaseMessaging.getInstance().getToken().addOnCompleteListener(
                        task -> {
                            if (task.isSuccessful()) {
                                Toast.makeText(this, "token ok", Toast.LENGTH_SHORT).show();
                                String token = task.getResult();
                                Log.i("token ---->>", token);
                                sendFirebaseToken(token);
                            } else {
                                Toast.makeText(this, "token fail", Toast.LENGTH_SHORT).show();

                                Toast.makeText(this, task.getException().toString(), Toast.LENGTH_SHORT).show();


                            }
                        }
                );

On a Googled android device it woks fine but on a Sony Xperia XA2 with Sailfish + Microg I have the exception:

IOException:SERVICE_NOT_AVAILABLE

On MicroG settings I have Cloud Messaging enabled and Connected. The same for Google device registration.

What could I check anymore?

Thanks

Start with the FirebaseMessaging.getInstance().getToken() call and the IOException:SERVICE_NOT_AVAILABLE result on the Sony Xperia XA2 running Sailfish with MicroG. Check the reported MicroG Cloud Messaging and device registration settings, then compare behavior with the working Google Android device. Done means identifying why token retrieval fails or documenting the missing configuration or compatibility issue.