Custom validator not working correctly in Angular reactive form

Made some changes:

• You had applied the validation to the complete form, i changed that to the email field only email: ['', [Validators.required, Validators.email, this.emailMatchValidator]],;

• Added the email field value & email field status to the screen to see the validation in action

• enter anything in the email field and move focus to get the validation in action

relevant HTML:

    <form class="form-group" [formGroup]='registerForm'>
        <input type="email" 
                        [ngClass]="{'is-invalid': registerForm.get('email').errors && registerForm.get('email').touched}
                          || registerForm.get('email').touched && registerForm.hasError('emailExists')"
                        class="form-control" 
                        formControlName="email" 
                        placeholder="Email">
                        <div class="invalid-feedback" *ngIf="registerForm.get('email').touched && registerForm.get('email').hasError('required')">
                          Email is required
                        </div>
                        <div class="invalid-feedback" *ngIf="registerForm.get('email').touched && registerForm.get('email').hasError('email')">
                          Invalid email address
                        </div>
                        <div class="invalid-feedback" *ngIf="registerForm.get('email').touched && registerForm.get('email').hasError('emailExists')">
                            Email address already in use
                          </div>
                    </form>

<hr/>
                    <b>email value:</b> {{registerForm.controls.email.value}} <br/>
                    <b>email status:</b> {{registerForm.controls.email.status}}

relevant TS:

import { Component } from '@angular/core';
import { FormBuilder, Validators, FormGroup, AbstractControl } from '@angular/forms'

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  name = 'Angular';
  constructor(private fb: FormBuilder) { }
  registerForm;

  ngOnInit() {
    this.createRegisterForm();
    console.log(this.registerForm);
  }

  createRegisterForm() {
    this.registerForm = this.fb.group({
      gender: ['male'],
      email: ['', [Validators.required, Validators.email, this.emailMatchValidator]],
      username: ['', [Validators.required, Validators.minLength(4), Validators.maxLength(10)]],
      knownAs: ['', Validators.required],
      dateOfBirth: [null, Validators.required],
      city: ['', Validators.required],
      country: ['', Validators.required],
      password: ['', [Validators.required, Validators.minLength(4), Validators.maxLength(8)]],
      confirmPassword: ['', Validators.required]
    }
      /*, {
          validator: [this.passwordMatchValidator, this.emailMatchValidator]
        }
        */
    );
  }

  passwordMatchValidator() {
    /* some implementation */
  }

  emailMatchValidator(control: AbstractControl) {
    if (control.value !== '[email protected]') {
      return false;
    } else {
      return { emailExists: true };
    }
  }

}

working stackblitz here