fix race condition

lib/submissions/ensure_result_generated.rb

@@ -32,6 +32,8 @@ module Submissions
 
         LockEvent.create!(key:, event_name: :complete)
 
+        submitter.documents.reset
+
         documents
       end
     rescue ActiveRecord::RecordNotUnique

lib/submissions/generate_result_attachments.rb

@@ -790,10 +790,10 @@ module Submissions
     def build_pdfs_index(submission, submitter: nil, flatten: true)
       latest_submitter = find_last_submitter(submission, submitter:)
 
-      Submissions::EnsureResultGenerated.call(latest_submitter) if latest_submitter
+      documents   = Submissions::EnsureResultGenerated.call(latest_submitter) if latest_submitter
+      documents ||= submission.schema_documents
 
-      documents   = latest_submitter&.documents&.preload(:blob).to_a.presence
-      documents ||= submission.schema_documents.preload(:blob)
+      ActiveRecord::Associations::Preloader.new(records: documents, associations: [:blob]).call
 
       attachment_uuids = Submissions.filtered_conditions_schema(submission).pluck('attachment_uuid')
       attachments_index = documents.index_by { |a| a.metadata['original_uuid'] || a.uuid }