Firebase collection update error in Ionic 3 app

Ionic Framework ionic-v3
1

I’m having problems with a Firebase vs Ionic 3 app when I create a new user in the app, I don’t know why I can create a new user only once every day and I try again in the same day but the database doesn’t update. It seems nonsense but that’s exactly waht’s happening. I have a Firebase file called firebase.ts with the database credentials to create the connection:

export const firebaseConfig = {
  // I replaced the data with "#" here for security reasons:
    apiKey: "###",
    authDomain: "###",
    databaseURL: "###",
    projectId: "###",
    storageBucket: "###",
    messagingSenderId: "###",
    appId: "###"
}

Then I have the register function in login.ts file:

createAccount() {
    let load = this.loadingCtrl.create();
    load.present();

    this.authProvider.register(this.registerForm)
      .then((res) => {
        let uid = res.user.uid;

        //organize data
        let data = {
          uid: uid,
          name: this.registerForm.name,
          email: this.registerForm.email
        };

        //Gravar usuario no firestore
        this.firebaseProvider.postUser(data)
          .then(() => {         
                this.storage.set('usuario', data)
                  .then(() => {
                    load.dismiss();
                    this.navCtrl.setRoot('HomePage');

                  })
          })
          .catch((err) => {
            load.dismiss();
          })
      })
      .catch((err) => {
        load.dismiss();
      })
  }

And the providers settings in firebase.ts from folder Providers :

import { Injectable } from "@angular/core";
import { AngularFirestore } from "angularfire2/firestore";
import "rxjs/add/operator/map";


@Injectable()
export class FirebaseProvider {
  constructor(private afs: AngularFirestore) {}

  //Save user on firestore
  saveUser = data =>
    this.afs
      .collection("Users")
      .doc(data.$key)
      .update(data);

  //Create user on firestore
  postUser = data =>
    this.afs
      .collection("Users")
      .doc(data.uid)
      .set(data);

      getUser(uid){
        return this.afs.firestore.collection('Users').doc(uid)
        .get();
       }
}

And finally authentication.ts file also in Providers folder:

import { Injectable } from '@angular/core';
import { AngularFireAuth } from "angularfire2/auth";

@Injectable()
export class AuthProvider {

  constructor(
    private afAuth: AngularFireAuth
  ) {
  }

  //Create new user
  register = (data) => this.afAuth.auth.createUserWithEmailAndPassword(data.email, data.password);

  //Login for existing user
  login = (data) => this.afAuth.auth.signInWithEmailAndPassword(data.email, data.password);
}

What could I do? Literally when I create one user, the first from the day, everything is fine but then the next time I try it, the database doesn’t update! Any help?