src/main/java/gc/mda/signal_batch/domain/gis/service/GisServiceV2.java

@@ -472,7 +472,6 @@ public class GisServiceV2 {
 
         // 4. 동일 선박 병합 (캐시 + DB 결과)
         List<CompactVesselTrack> merged = mergeTracksByVessel(allTracks);
-        allTracks.clear();
 
         return merged;
     }