在开发中，JSON数据正常显示，但在生产环境中显示不正确。

这是我的routes.rb文件

namespace :api do
    get 'suggestions/jobs', to: "suggestions#jobs"
end

我的控制器

class Api::SuggestionsController < ApplicationController
    def jobs
        @jobs = Job.job_title_search(params[:q])   #.select(:title, :label).distinct
        if @jobs.present?
            render json: @jobs, status: :ok
        else
            render json: "Not Found", status: :ok
        end
    end
end

和模型

def self.job_title_search(q)
    where('title LIKE ?', "%#{q}%").select(:title, :label).distinct
end

在开发环境中，例如localhost:3000/api/suggestions/jobs?q=dev，数据示例如下：

[

这意味着它正常工作，但是当我部署到Heroku上，例如example.herokuapp.com/api/suggestions/jobs?q=dev，出现如下错误：

SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data

我知道有类似以下代码的"Not Found"：

render json: "Not Found", status: :ok

我的问题是为什么相同的代码在Heroku上无法工作？我应该怎么做？

database.yml文件内容如下：

# SQLite version 3.x
#   gem install sqlite3
#
#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
#
default: &default
  adapter: sqlite3
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  timeout: 5000
development:
  <<: *default
  database: db/development.sqlite3
# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: db/test.sqlite3
production:
  <<: *default
  database: my_project_production
  username: my_project
  password: <%= ENV['MY_PROJECT_DATABASE_PASSWORD'] %>

感谢任何帮助。谢谢。