Fix

Author: benchaplin

server/src/main/java/org/elasticsearch/action/search/SearchQueryThenFetchAsyncAction.java

@@ -869,7 +869,10 @@ void onShardDone() {
                 }
             }
 
-            ActionListener.respondAndRelease(channelListener, new BytesTransportResponse(out.moveToBytesReference()));
+            ActionListener.respondAndRelease(
+                channelListener,
+                new BytesTransportResponse(out.moveToBytesReference(), out.getTransportVersion())
+            );
         }
 
         // Writes the "successful" response (see NodeQueryResponse for the corresponding read logic)

server/src/main/java/org/elasticsearch/search/SearchService.java

@@ -296,7 +296,7 @@ public class SearchService extends AbstractLifecycleComponent implements IndexEv
         Setting.Property.NodeScope
     );
 
-    private static final boolean BATCHED_QUERY_PHASE_FEATURE_FLAG = new FeatureFlag("batched_query_phase").isEnabled();
+    public static final boolean BATCHED_QUERY_PHASE_FEATURE_FLAG = new FeatureFlag("batched_query_phase").isEnabled();
 
     /**
      * The size of the buffer used for memory accounting.