diff --git a/AMSS_NCKU_source/bssn_cuda_step.C b/AMSS_NCKU_source/bssn_cuda_step.C
index 37a9469..83fd6f5 100644
--- a/AMSS_NCKU_source/bssn_cuda_step.C
+++ b/AMSS_NCKU_source/bssn_cuda_step.C
@@ -889,15 +889,13 @@ void bssn_class::Step_MainPath_GPU(int lev, int YN)
 
   if (!ERROR && keep_stage_sync_on_device)
   {
-    MyList<var> *final_host_lists[] = {StateList, OldStateList, SynchList_cor, SynchList_pre};
-    const int final_host_list_count = sizeof(final_host_lists) / sizeof(final_host_lists[0]);
-    for (int list_i = 0; list_i < final_host_list_count && !ERROR; ++list_i)
-    {
-      const double t0 = profile_enabled ? MPI_Wtime() : 0.0;
-      stage_download_patch_list(final_host_lists[list_i], true);
-      if (profile_enabled)
-        stage_profile_add(lev, STAGE_PROFILE_DOWNLOAD, MPI_Wtime() - t0);
-    }
+    // After the swaps above, only StateList points at arrays updated during this step.
+    // OldStateList/SynchList_cor remain valid on host because their backing arrays were
+    // read-only during the RK step, and SynchList_pre is reused only as scratch later.
+    const double t0 = profile_enabled ? MPI_Wtime() : 0.0;
+    stage_download_patch_list(StateList, true);
+    if (profile_enabled)
+      stage_profile_add(lev, STAGE_PROFILE_DOWNLOAD, MPI_Wtime() - t0);
   }
 
   if (profile_enabled)