serializers not working in nested json

Expected behavior vs actual behavior

Expected:

{
    "code": 0,
    "message": "0",
    "data": {
        "id": 54,
        "email": "test@test.com"
    }
}

actual:

{
    "code": 0,
    "message": "0",
    "data": {
        "id": 54,
        "email": "nimaqu.dev20@nimaqu.com",
        "created_at": "2022-09-17T03:54:03.422Z",
        "updated_at": "2022-09-17T03:54:23.141Z",
        "jti": "1e58936c-ef85-4447-bcbf-70fd359f110a"
    }
}

Steps to reproduce

(e.g., detailed walkthrough, runnable script, example application) works: render json: user

{
    "id": 54,
    "email": "nimaqu.dev20@nimaqu.com"
}

not working: render json: { code: 0, message: '0', data: user }

{
    "code": 0,
    "message": "0",
    "data": {
        "id": 54,
        "email": "nimaqu.dev20@nimaqu.com",
        "created_at": "2022-09-17T03:54:03.422Z",
        "updated_at": "2022-09-17T03:54:23.141Z",
        "jti": "1e58936c-ef85-4447-bcbf-70fd359f110a"
    }
}

user_serializer.rb:

class UserSerializer < ActiveModel::Serializer
  attributes :id, :email
end

Environment

ActiveModelSerializers Version (commit ref if not on tag):

Output of ruby -e "puts RUBY_DESCRIPTION": ruby 2.7.6p219 (2022-04-12 revision c9c2245c0a) [x64-mingw32]

OS Type & Version: Windows 11 Integrated application and version (e.g., Rails, Grape, etc): Rails 5

Backtrace

(e.g., provide any applicable backtraces from your application)

Started GET "/api/v1/client/accounts/brief" for 127.0.0.1 at 2022-11-28 02:26:26 -0600
  User Load (0.4ms)  SELECT `users`.* FROM `users` WHERE `users`.`id` = 54 LIMIT 1
Processing by UsersController#user_brief as */*
  CACHE User Load (0.0ms)  SELECT `users`.* FROM `users` WHERE `users`.`id` = 54 LIMIT 1
  ↳ app/controllers/users_controller.rb:31:in `user_brief'
[active_model_serializers] Rendered ActiveModel::Serializer::Null with Hash (0.36ms)
Completed 200 OK in 2ms (Views: 0.9ms | ActiveRecord: 0.0ms | Allocations: 920)

Additonal helpful information

(e.g., Gemfile.lock, configurations, PR containing a failing test, git bisect results)

rails-api / active_model_serializers