Ionic4 ngSubmit is not firing on submit

Using Ionic4 for the first time and struggling with ngSubmit not triggering the respective method in the login page. Although its always successfully hitting the LoginPage constructor and AuthService constructor. All the respective modules have been imported and there are no console errors too. What am i doing wrong ?

login.page.html:

<ion-header>
  <ion-toolbar>
    <ion-title>
      Login
    </ion-title>
  </ion-toolbar>
</ion-header>
<ion-content>   
    <form (ngSubmit)="login()" [formGroup]="loginForm">
        <ion-grid>          
            <ion-row>
                    <ion-col>
                        <ion-item>
                        <ion-input type="text" placeholder="Email" formControlName="email" style="width:50%;"></ion-input>
                    </ion-item>
                    </ion-col>
                </ion-row>
                <ion-row>
                    <ion-col col-3>
                        <ion-item>
                        <ion-input type="password" placeholder="Password" formControlName="password" style="width:50%;"></ion-input>
                    </ion-item>
                    </ion-col>
                </ion-row>
        </ion-grid>
        <div padding-horizontal>
            <div class="form-error">{{loginError}}</div>
        </div>                  
            <ion-grid>
                <ion-row>
                    <ion-col>                       
                            <ion-button type="submit" [disabled]="!loginForm.valid" color="primary">Log in</ion-button>                     
                            &nbsp;&nbsp;                        
                            <a href="#">Forgot password?</a>
                    </ion-col>                  
                </ion-row>
                <ion-row>
                    <ion-col>
                <ion-button icon-left block clear (click)="loginWithGoogle()" color="secondary">
                    <ion-icon name="logo-google"></ion-icon>
                    Log in with Google
                </ion-button>
                <ion-button icon-left block clear (click)="signup()" color="primary">
                        <ion-icon name="person-add"></ion-icon>
                        Sign up
                    </ion-button>
            </ion-col>          
            </ion-row>
            </ion-grid>     
    </form> 
</ion-content>

login.page.ts:

import { Component, OnInit } from '@angular/core';
import { AuthService } from '../common/services/auth.service';
import { FormGroup, FormBuilder, Validators } from '@angular/forms';
import { Router } from '@angular/router';

@Component({
  selector: 'app-login',
  templateUrl: './login.page.html',
  styleUrls: ['./login.page.scss'],
})

export class LoginPage implements OnInit {
  loginForm: FormGroup;
  loginError: string;

  constructor(private auth:AuthService,
              private router:Router,
              private fb: FormBuilder) 
  {
    this.loginForm = this.fb.group({
            email: ['', Validators.compose([Validators.required, Validators.email])],
            password: ['', Validators.compose([Validators.required, Validators.minLength(6)])]
        });
  }

  ngOnInit() {}  

  login() {  
    alert('login');
        let data = this.loginForm.value;

        if (!data.email) {
            return;
        }

        let credentials = {
            email: data.email,
            password: data.password
    };

        this.auth.signInWithEmail(credentials)
            .then(
                () => this.router.navigate(['/home']),
                error => this.loginError = error.message
            );
    }  
}

login.module.ts:

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule,ReactiveFormsModule } from '@angular/forms';
import { Routes, RouterModule } from '@angular/router';
import { IonicModule } from '@ionic/angular';

import { LoginPage } from './login.page';

const routes: Routes = [
  {
    path: '',
    component: LoginPage
  }
];

@NgModule({
  imports: [
    CommonModule,
    FormsModule,
    ReactiveFormsModule,
    IonicModule,
    RouterModule.forChild(routes),
  ],
  entryComponents: [LoginPage],
  declarations: [LoginPage]
})
export class LoginPageModule {}

auth.service.ts:

import { Injectable } from '@angular/core';
import { AngularFireAuth } from 'angularfire2/auth';
import * as firebase from 'firebase/app';
import AuthProvider = firebase.auth.AuthProvider;

@Injectable({
  providedIn: 'root'
})
export class AuthService {
  private user: firebase.User;

    constructor(public afAuth: AngularFireAuth) {
        afAuth.authState.subscribe(user => {            
            this.user = user;
        });
    }

    signInWithEmail(credentials) {
        console.log('Sign in with email');
        return this.afAuth.auth.signInWithEmailAndPassword(credentials.email,
             credentials.password);
    }
}

ngSubmit is reloading the complete page and hence its hitting only login constructor but not the respective method. Removed (ngSubmit) on <form>, type="submit" on <ion-button>, added (click)="login()" event to <ion-button>. It started working.