id_username showing up in django form without reason

I'm looking for some help with my custom user model. For a reason I cannot understand the field id_username pops up after clicking on the submit button.

This field is missing from the form which I have cut down to {{ form.as_ p }} in the html.

login.html

      <div class="mx-auto" style="max-width: 30rem;">
    <!-- Card -->
    <div class="card card-lg mb-5">
      <div class="card-body">
        <!-- Form -->
        <form class="js-validate needs-validation" action="{% url 'login' %}" method="POST">
          {% csrf_token %}

          <div class="text-center">
            <div class="mb-5">
              <h1 class="display-5">Sign in</h1>
              <p>Dont have an account yet? <a class="link" href="{% url 'accounts:register' %}">Sign up here</a></p>
            </div>

            <div class="d-grid mb-4">
              <a class="btn btn-white btn-lg" href="#">
                <span class="d-flex justify-content-center align-items-center">
                  <img class="avatar avatar-xss me-2" src="{% static '/assets/svg/brands/google-icon.svg' %}" alt="Image Description">
                  Sign in with Google
                </span>
              </a>
            </div>

            <span class="divider-center text-muted mb-4">OR</span>
          </div>

          <!-- Form -->
          <div class="mb-4">

            <!-- End Form Check -->
            {{ form.as_p }}

            <label class="form-label w-100 d-flex">Your email</label>


            <span class="invalid-feedback">Please enter a valid email address.</span>

            <label class="form-label w-100" tabindex="0">
              <span class="d-flex justify-content-between align-items-center">
                <span>Password</span>
                <a class="form-label-link mb-0" href="./authentication-reset-password-basic.html">Forgot Password?</a>
              </span>
            </label>
            <div class="input-group-merge">
                                
              <a id="changePassTarget" class="input-group-append input-group-text" href="javascript:;">
              <i id="changePassIcon" class="bi-eye"></i>
              </a>
            </div>       
          </div>

        

          <div class="d-grid">
          <button type="submit" class="btn-block btn btn-primary">Sign in</button>

          </div>
        </form>
        <!-- End Form -->
      </div>
    </div>
    <!-- End Card -->

    <!-- Footer -->

urls.py

path('login/', LoginView.as_view(template_name="registration/login.html"), name='login'),

forms.py

class LoginForm(forms.Form):
    email    = forms.EmailField(label='Email', widget=forms.TextInput(attrs={'placeholder': 'Email'}))
    password = forms.CharField(widget=forms.PasswordInput(attrs={'placeholder': 'Password'}))

views.py

class LoginView(FormView):
    form_class = LoginForm
    success_url = '/about/'
    template_name = 'registration/login.html'

    def form_valid(self, form):
        request = self.request
        next_ = request.GET.get('next')
        next_post = request.POST.get('next')
        redirect_path = next_ or next_post or None
        email  = form.cleaned_data.get("email")
        password  = form.cleaned_data.get("password")
        user = authenticate(request, username=email, password=password)
        if user is not None:
            login(request, user)
            try:
                del request.session['guest_email_id']
            except:
                pass
            if is_safe_url(redirect_path, request.get_host()):
                return redirect(redirect_path)
            else:
                return redirect("/about/")
        return super(LoginView, self).form_invalid(form)

models.py

class User(AbstractBaseUser):
    email = models.EmailField(
        verbose_name='email address',
        max_length=255,
        unique=True,
        help_text='Email Address'
    )
    active      = models.BooleanField(default=True)
    staff       = models.BooleanField(default=False) # a admin user; non super-user
    admin       = models.BooleanField(default=False) # a superuser
    timestamp   = models.DateTimeField(auto_now_add=True)

    USERNAME_FIELD = "email"
    REQUIRED_FIELDS = [] # Email & Password are required by default.

    objects = UserManager()

    def get_full_name(self):
        # The user is identified by their email address
        return self.email

   ... etc ...

    @property
    def is_active(self):
        "Is the user active?"
        return self.active

    objects = UserManager()

Visually it can be followed that I click login on accounts/login where you can see the id_email and id_password. On click follows is a form error and the emergence of id_username from the depths of hell.

First form On Click

Can anyone please explain to me why this is possibly happening? It's really driving me nuts.