diff --git a/SHiNE-server/shine-server-net-protocol/src/main/java/server/sync/AddBlockSyncService.java b/SHiNE-server/shine-server-net-protocol/src/main/java/server/sync/AddBlockSyncService.java
index b2fd337f..2e4741ab 100644
--- a/SHiNE-server/shine-server-net-protocol/src/main/java/server/sync/AddBlockSyncService.java
+++ b/SHiNE-server/shine-server-net-protocol/src/main/java/server/sync/AddBlockSyncService.java
@@ -114,6 +114,12 @@ public final class AddBlockSyncService {
             return;
         }
 
+        if (firstTry.serverAlreadyHasBlock(blockNumber)) {
+            log.info("AddBlock sync skipped: partner already has block. partner={} blockchainName={} blockNumber={} remoteLast={}",
+                    partner.getLogin(), blockchainName, blockNumber, firstTry.serverLastGlobalNumber());
+            return;
+        }
+
         if (!firstTry.needsBackfill()) {
             log.warn("AddBlock sync failed without backfill: partner={} blockchainName={} blockNumber={} code={}",
                     partner.getLogin(), blockchainName, blockNumber, firstTry.code());
@@ -123,7 +129,7 @@ public final class AddBlockSyncService {
         int remoteLast = firstTry.serverLastGlobalNumber();
         int fromBlockNumber = remoteLast + 1;
         if (fromBlockNumber > blockNumber) {
-            log.warn("AddBlock sync inconsistent backfill window: partner={} blockchainName={} remoteLast={} target={}",
+            log.info("AddBlock sync skipped: partner already caught up during backfill window. partner={} blockchainName={} remoteLast={} target={}",
                     partner.getLogin(), blockchainName, remoteLast, blockNumber);
             return;
         }
@@ -295,6 +301,12 @@ public final class AddBlockSyncService {
         boolean needsBackfill() {
             return !ok && ("bad_prev_hash".equalsIgnoreCase(code) || "bad_block_number".equalsIgnoreCase(code));
         }
+
+        boolean serverAlreadyHasBlock(int targetBlockNumber) {
+            return !ok
+                    && serverLastGlobalNumber != Integer.MIN_VALUE
+                    && serverLastGlobalNumber >= targetBlockNumber;
+        }
     }
 
     private static final class SyncWsListener implements WebSocket.Listener {
diff --git a/VERSION.properties b/VERSION.properties
index e63d5594..a83f4e2b 100644
--- a/VERSION.properties
+++ b/VERSION.properties
@@ -1,2 +1,2 @@
 client.version=1.2.354
-server.version=1.2.323
+server.version=1.2.324