Devise, lockable does not reset failed_attempts after unlocking

I have model Person which uses Devise it has :lockable

I have added these fields in my model:

field :failed_attempts, type: Integer, default: 0
field :locked_at,       type: Time

In my config/initializers/devise.rb file I have that kind of settings:

config.lock_strategy = :failed_attempts
config.unlock_strategy = :time
config.maximum_attempts = 10
config.unlock_in = 30.minutes

I get password and make validation:

if person.valid_password?(params[:password])

   # do something if password is right
else

   person.failed_attempts += 1
   person.save

   if person.failed_attempts >= person.class.maximum_attempts
      person.lock_access!
      PersonMailer.blocked_email(person).deliver_later
   end

end

If password is wrong I increment failed_attemps and then check if it more than maximum attempts. I it is, it will call lock_access! method.

Then I check if lock time is expired or not:

if person.access_locked?
   if person.locked_at && person.locked_at < person.class.unlock_in.ago
     person.unlock_access!
   else
     error!('Access is locked', 401)
   end
 end

If time of blocking is expired, it calls unlock_access! method.

Now here is the problem. When unlcock_access! is called it makes access_locked? false, but does not reset locked_at and failed_attempts values.

What did I miss?

via Chebli Mohamed