Rails 5.1.5 ( redirect to login but not saving data [omniauth + Devise]

class User < ApplicationRecord

  has_many :articles
  has_many :identities
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable, :omniauthable

  validates_presence_of :name

  def facebook
    identities.where( :provider => "facebook").first
  end
  
  def facebook_client
    @facebook_client ||= Facebook.client(access_token: facebook.accesstoken)
  end

end

class User < ApplicationRecord

  has_many :articles
  has_many :identities
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable, :omniauthable

  validates_presence_of :name

  def facebook
    identities.where( :provider => "facebook").first
  end
  
  def facebook_client
    @facebook_client ||= Facebook.client(access_token: facebook.accesstoken)
  end

end

class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
    def facebook
        generic_callback('facebook')
    end

    def generic_callback(provider)
        @identity = Identity.find_for_oauth env["omniauth.auth"]
        @user = @identity.user || User.find_by(email: @identity.email) || current_user
        if @user.nil?
            @user = User.create(email: @identity.email || "")
            @identity.update_attribute(:user_id, @user.id)
        end

        if @user.email.blank? && @identity.email
            @user.update_attribute(:email, @identity.email)
        end

        if @user.persisted?
            @identity.update_attribute(:user_id , @user.id)
            @user = User.find @user.id
            sign_in_and_redirect @user,event: :authentication
        else
            session["devise.#{provider}_data"] = env["omniauth.auth"]
            redirect_to new_user_registration_url
        end
    end
      def upgrade
    scope = nil
    if params[:provider] == "google_oauth2"
      scope = "email,profile,offline,https://www.googleapis.com/auth/admin.directory.user"
    end

    redirect_to user_omniauth_authorize_path( params[:provider] ), flash: { scope: scope }
  end

  def setup
    request.env['omniauth.strategy'].options['scope'] = flash[:scope] || request.env['omniauth.strategy'].options['scope']
    render :text => "Setup complete.", :status => 404
  end
end

1. Have you migrated the additional columns to your user model?  e.g. 'provider', 'uid'?
2. Have you also added your app details in config/initializers/devise.rb?
   1. config.omniauth :facebook, ENV['FACEBOOK_APP_ID'], ENV['FACEBOOK_APP_SECRET'], scope: "email", info_fields: 'email, first_name, last_name'