Ordering doesn't work without RoR shutdown

Sup. I deal with the problem for three days. In my project where I use search in model Record I've implemented two buttons: "Delete index" and "Refresh index". First button is redirecting page to controller delete_index where I execute Record.tire.index.delete. Second button is redirecting page to controller refresh_index where the index is refreshing via Sidekiq worker, where I execute Record.import. Main problem: When I press "Delete index" - it works correct; When I press "Refresh index" - the index is imports correctly but order by date is fully broken. I've attached some screenshots with the problem. Screenshot without problem: order is working:

Screenshot with problem: order is broken after I pressed "Delete index" and "Refresh index":

I can fix second case only if I do actions in this sequence:

Execute Record.tire.index.delete
Shutdown RoR server
Execute RoR server with rails s
Execure Record.import

Some piece of code: records_controller.rb:

def refresh_index
  if params[:refresh]
    RecordsImport.perform_async('exec')
    redirect_to "/search"
  end
end
def delete_index
  if params[:delete]
    Record.tire.index.delete
    redirect_to "/search"
  end
end

records_import.rb:

class RecordsImport
  include Sidekiq::Worker
  def perform(name)
    if name == 'exec'
      Record.import
    else
      return
    end
  end
end

My mapping in record.rb model:

tire do
  mapping do
    indexes :id, index: :not_analyzed
    indexes :timestamp, type: 'date', format: 'dd.MM.yyyy HH:mm', include_in_all: false
    indexes :title, analyzer: 'snowball'
  end
end

My search query:

@records = Record.search page: params[:page], per_page: 50 do
  query do
    string: "*"
  end
  sort do
    by :timestamp, order: "desc"
  end
end

Maybe I'm doing something wrong, but all suggestions welcome. Thanks in advance and sorry for my bad English.

karmi / retire

Ordering doesn't work without RoR shutdown #990