Tweak exception logging, sync stale behavior

app/models/concerns/syncable.rb

@@ -11,17 +11,18 @@ module Syncable
 
   def sync_later(parent_sync: nil, window_start_date: nil, window_end_date: nil)
     Sync.transaction do
-      # Expire any previous in-flight syncs for this record that exceeded the
-      # global staleness window.
-      syncs.stale_candidates.find_each(&:mark_stale!)
+      # Since we're scheduling a new sync, mark old syncs for this syncable as stale
+      self.syncs.incomplete.find_each(&:mark_stale!)
 
-      new_sync = syncs.create!(
+      new_sync = self.syncs.create!(
         parent: parent_sync,
         window_start_date: window_start_date,
         window_end_date: window_end_date
       )
 
       SyncJob.perform_later(new_sync)
+
+      new_sync
     end
   end