use submission completed_at

app/controllers/templates_archived_submissions_controller.rb

@@ -10,7 +10,7 @@ class TemplatesArchivedSubmissionsController < ApplicationController
     @submissions = Submissions::Filter.call(@submissions, current_user, params)
 
     @submissions = if params[:completed_at_from].present? || params[:completed_at_to].present?
-                     @submissions.order(Submitter.arel_table[:completed_at].maximum.desc)
+                     @submissions.order(completed_at: :desc)
                    else
                      @submissions.order(id: :desc)
                    end