Cookiecutter-django custom User field is never saved to DB

I'm struggling with a banal (I guess) issue with cookiecutter-django...

I added the field invitation_code to users.models.User:

class User(AbstractUser):
    """
    Default custom user model for pintable.
    If adding fields that need to be filled at user signup,
    check forms.SignupForm and forms.SocialSignupForms accordingly.
    """

    #: First and last name do not cover name patterns around the globe
    name = CharField(_("Full name"), max_length=255, null=True, blank=True)
    first_name = None  # type: ignore
    last_name = None  # type: ignore

    invitation_code = CharField(
        _("Invitation code"), max_length=8, null=True, blank=True
    )

Then I added the same field to users.forms.UserSignupForm:

class UserSignupForm(SignupForm):
    """
    Form that will be rendered on a user sign up section/screen.
    Default fields will be added automatically.
    Check UserSocialSignupForm for accounts created from social.
    """

    invitation_code = CharField(
        label=_("Invitation code"),
        widget=TextInput(attrs={"placeholder": _("Invitation code")}),
    )

The problem is that when a new user is saved to DB, the invitation_code field is always None. What am I missing..?

Thanks for your help!

Solved!

To make things work I had to customize users.adapters.AccountAdapter as well:

def save_user(self, request, user, form, commit=True):
        dummy_user = super().save_user(request, user, form, commit=False)
        dummy_user.invitation_code = form.cleaned_data["invitation_code"]
        if commit:
            dummy_user.save()