diff --git a/api/service/explorer/service.go b/api/service/explorer/service.go
index bed0e2272..112d4dda7 100644
--- a/api/service/explorer/service.go
+++ b/api/service/explorer/service.go
@@ -176,7 +176,7 @@ func (s *Service) GetTotalSupply(w http.ResponseWriter, r *http.Request) {
 // GetNodeSync returns status code 500 if node is not in sync
 func (s *Service) GetNodeSync(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
-	sync := !s.stateSync.IsOutOfSync(s.blockchain)
+	sync := !s.stateSync.IsOutOfSync(s.blockchain, false)
 	if !sync {
 		w.WriteHeader(http.StatusTeapot)
 	}
diff --git a/api/service/syncing/syncing.go b/api/service/syncing/syncing.go
index cf37f1de7..124e45d92 100644
--- a/api/service/syncing/syncing.go
+++ b/api/service/syncing/syncing.go
@@ -899,18 +899,36 @@ func (ss *StateSync) GetMaxPeerHeight() uint64 {
 }
 
 // IsOutOfSync checks whether the node is out of sync from other peers
-func (ss *StateSync) IsOutOfSync(bc *core.BlockChain) bool {
+func (ss *StateSync) IsOutOfSync(bc *core.BlockChain, doubleCheck bool) bool {
 	if ss.syncConfig == nil {
 		return true // If syncConfig is not instantiated, return not in sync
 	}
-	otherHeight := ss.getMaxPeerHeight(false)
+	otherHeight1 := ss.getMaxPeerHeight(false)
+	lastHeight := bc.CurrentBlock().NumberU64()
+	wasOutOfSync := lastHeight+inSyncThreshold < otherHeight1
+
+	if !doubleCheck {
+		utils.Logger().Info().
+			Uint64("OtherHeight", otherHeight1).
+			Uint64("lastHeight", lastHeight).
+			Msg("[SYNC] Checking sync status")
+		return wasOutOfSync
+	}
+	time.Sleep(3 * time.Second)
+	// double check the sync status after 3 second to confirm (avoid false alarm)
+
+	otherHeight2 := ss.getMaxPeerHeight(false)
 	currentHeight := bc.CurrentBlock().NumberU64()
-	utils.Logger().Debug().
-		Uint64("OtherHeight", otherHeight).
-		Uint64("MyHeight", currentHeight).
-		Bool("IsOutOfSync", currentHeight+inSyncThreshold < otherHeight).
+
+	isOutOfSync := currentHeight+inSyncThreshold < otherHeight2
+	utils.Logger().Info().
+		Uint64("OtherHeight1", otherHeight1).
+		Uint64("OtherHeight2", otherHeight2).
+		Uint64("lastHeight", lastHeight).
+		Uint64("currentHeight", currentHeight).
 		Msg("[SYNC] Checking sync status")
-	return currentHeight+inSyncThreshold < otherHeight
+	// Only confirm out of sync when the node has lower height and didn't move in heights for 2 consecutive checks
+	return wasOutOfSync && isOutOfSync && lastHeight == currentHeight
 }
 
 // SyncLoop will keep syncing with peers until catches up
@@ -978,7 +996,7 @@ func (ss *StateSync) addConsensusLastMile(bc *core.BlockChain, consensus *consen
 			return errors.Wrap(err, "failed to InsertChain")
 		}
 	}
-	consensus.FBFTLog.PruneCacheBeforeBlock(bc.CurrentBlock().NumberU64() + 1)
+	consensus.FBFTLog.PruneCacheBeforeBlock(bc.CurrentBlock().NumberU64())
 	return nil
 }
 
diff --git a/consensus/consensus_msg_sender.go b/consensus/consensus_msg_sender.go
index 9d1da5149..bbd63a746 100644
--- a/consensus/consensus_msg_sender.go
+++ b/consensus/consensus_msg_sender.go
@@ -56,7 +56,7 @@ func (sender *MessageSender) Reset(blockNum uint64) {
 }
 
 // SendWithRetry sends message with retry logic.
-func (sender *MessageSender) SendWithRetry(blockNum uint64, msgType msg_pb.MessageType, groups []nodeconfig.GroupID, p2pMsg []byte) error {
+func (sender *MessageSender) SendWithRetry(blockNum uint64, msgType msg_pb.MessageType, groups []nodeconfig.GroupID, p2pMsg []byte, immediate bool) error {
 	if sender.retryTimes != 0 {
 		msgRetry := MessageRetry{blockNum: blockNum, groups: groups, p2pMsg: p2pMsg, msgType: msgType, retryCount: 0}
 		atomic.StoreUint32(&msgRetry.isActive, 1)
@@ -65,7 +65,10 @@ func (sender *MessageSender) SendWithRetry(blockNum uint64, msgType msg_pb.Messa
 			sender.Retry(&msgRetry)
 		}()
 	}
-	return sender.host.SendMessageToGroups(groups, p2pMsg)
+	if immediate {
+		return sender.host.SendMessageToGroups(groups, p2pMsg)
+	}
+	return nil
 }
 
 // SendWithoutRetry sends message without retry logic.
diff --git a/consensus/consensus_v2.go b/consensus/consensus_v2.go
index cb50c6258..3fc719c46 100644
--- a/consensus/consensus_v2.go
+++ b/consensus/consensus_v2.go
@@ -149,12 +149,17 @@ func (consensus *Consensus) finalCommit() {
 	}
 
 	// if leader successfully finalizes the block, send committed message to validators
+	sendImmediately := false
+	if !consensus.IsLeader() || block.IsLastBlockInEpoch() {
+		sendImmediately = true
+	}
 	if err := consensus.msgSender.SendWithRetry(
 		block.NumberU64(),
 		msg_pb.MessageType_COMMITTED, []nodeconfig.GroupID{
 			nodeconfig.NewGroupIDByShardID(nodeconfig.ShardID(consensus.ShardID)),
 		},
-		p2p.ConstructMessage(msgToSend)); err != nil {
+		p2p.ConstructMessage(msgToSend),
+		sendImmediately); err != nil {
 		consensus.getLogger().Warn().Err(err).Msg("[finalCommit] Cannot send committed message")
 	} else {
 		consensus.getLogger().Info().
@@ -195,13 +200,22 @@ func (consensus *Consensus) finalCommit() {
 	// If still the leader, send commit sig/bitmap to finish the new block proposal,
 	// else, the block proposal will timeout by itself.
 	if consensus.IsLeader() {
-		go func() {
-			select {
-			case consensus.CommitSigChannel <- commitSigAndBitmap:
-			case <-time.After(6 * time.Second):
-				utils.Logger().Error().Err(err).Msg("[finalCommit] channel not received after 6s for commitSigAndBitmap")
-			}
-		}()
+		if block.IsLastBlockInEpoch() {
+			// No pipelining
+			go func() {
+				consensus.getLogger().Info().Msg("[finalCommit] sending block proposal signal")
+				consensus.ReadySignal <- SyncProposal
+			}()
+		} else {
+			// pipelining
+			go func() {
+				select {
+				case consensus.CommitSigChannel <- commitSigAndBitmap:
+				case <-time.After(6 * time.Second):
+					utils.Logger().Error().Err(err).Msg("[finalCommit] channel not received after 6s for commitSigAndBitmap")
+				}
+			}()
+		}
 	}
 }
 
@@ -290,12 +304,14 @@ func (consensus *Consensus) Start(
 			case <-consensus.syncReadyChan:
 				consensus.getLogger().Info().Msg("[ConsensusMainLoop] syncReadyChan")
 				consensus.mutex.Lock()
-				consensus.SetBlockNum(consensus.Blockchain.CurrentHeader().Number().Uint64() + 1)
-				consensus.SetViewIDs(consensus.Blockchain.CurrentHeader().ViewID().Uint64() + 1)
-				mode := consensus.UpdateConsensusInformation()
-				consensus.current.SetMode(mode)
+				if consensus.blockNum < consensus.Blockchain.CurrentHeader().Number().Uint64()+1 {
+					consensus.SetBlockNum(consensus.Blockchain.CurrentHeader().Number().Uint64() + 1)
+					consensus.SetViewIDs(consensus.Blockchain.CurrentHeader().ViewID().Uint64() + 1)
+					mode := consensus.UpdateConsensusInformation()
+					consensus.current.SetMode(mode)
+					consensus.getLogger().Info().Str("Mode", mode.String()).Msg("Node is IN SYNC")
+				}
 				consensus.mutex.Unlock()
-				consensus.getLogger().Info().Str("Mode", mode.String()).Msg("Node is IN SYNC")
 
 			case <-consensus.syncNotReadyChan:
 				consensus.getLogger().Info().Msg("[ConsensusMainLoop] syncNotReadyChan")
@@ -393,7 +409,7 @@ func (consensus *Consensus) Start(
 				consensus.announce(newBlock)
 
 			case viewID := <-consensus.commitFinishChan:
-				consensus.getLogger().Info().Msg("[ConsensusMainLoop] commitFinishChan")
+				consensus.getLogger().Info().Uint64("viewID", viewID).Msg("[ConsensusMainLoop] commitFinishChan")
 
 				// Only Leader execute this condition
 				func() {
@@ -487,9 +503,26 @@ func (consensus *Consensus) preCommitAndPropose(blk *types.Block) error {
 		return errors.New("block to pre-commit is nil")
 	}
 
+	leaderPriKey, err := consensus.GetConsensusLeaderPrivateKey()
+	if err != nil {
+		consensus.getLogger().Error().Err(err).Msg("[preCommitAndPropose] leader not found")
+		return err
+	}
+
+	// Construct committed message
 	consensus.mutex.Lock()
-	bareMinimumCommit := consensus.constructQuorumSigAndBitmap(quorum.Commit)
+	network, err := consensus.construct(msg_pb.MessageType_COMMITTED, nil, []*bls.PrivateKeyWrapper{leaderPriKey})
 	consensus.mutex.Unlock()
+	if err != nil {
+		consensus.getLogger().Warn().Err(err).
+			Msg("[preCommitAndPropose] Unable to construct Committed message")
+		return err
+	}
+	msgToSend, FBFTMsg :=
+		network.Bytes,
+		network.FBFTMsg
+	bareMinimumCommit := FBFTMsg.Payload
+	consensus.FBFTLog.AddMessage(FBFTMsg)
 
 	blk.SetCurrentCommitSig(bareMinimumCommit)
 
@@ -498,6 +531,22 @@ func (consensus *Consensus) preCommitAndPropose(blk *types.Block) error {
 		return err
 	}
 
+	// if leader successfully finalizes the block, send committed message to validators
+	if err := consensus.msgSender.SendWithRetry(
+		blk.NumberU64(),
+		msg_pb.MessageType_COMMITTED, []nodeconfig.GroupID{
+			nodeconfig.NewGroupIDByShardID(nodeconfig.ShardID(consensus.ShardID)),
+		},
+		p2p.ConstructMessage(msgToSend),
+		true); err != nil {
+		consensus.getLogger().Warn().Err(err).Msg("[preCommitAndPropose] Cannot send committed message")
+	} else {
+		consensus.getLogger().Info().
+			Str("blockHash", blk.Hash().Hex()).
+			Uint64("blockNum", consensus.blockNum).
+			Msg("[preCommitAndPropose] Sent Committed Message")
+	}
+
 	// Send signal to Node to propose the new block for consensus
 	consensus.getLogger().Info().Msg("[preCommitAndPropose] sending block proposal signal")
 
@@ -573,7 +622,7 @@ func (consensus *Consensus) commitBlock(blk *types.Block, committedMsg *FBFTMess
 
 // SetupForNewConsensus sets the state for new consensus
 func (consensus *Consensus) SetupForNewConsensus(blk *types.Block, committedMsg *FBFTMessage) {
-	atomic.AddUint64(&consensus.blockNum, 1)
+	atomic.StoreUint64(&consensus.blockNum, blk.NumberU64()+1)
 	consensus.SetCurBlockViewID(committedMsg.ViewID + 1)
 	consensus.LeaderPubKey = committedMsg.SenderPubkeys[0]
 	// Update consensus keys at last so the change of leader status doesn't mess up normal flow
diff --git a/consensus/leader.go b/consensus/leader.go
index 7ae69bb59..26c751ff9 100644
--- a/consensus/leader.go
+++ b/consensus/leader.go
@@ -80,7 +80,7 @@ func (consensus *Consensus) announce(block *types.Block) {
 	if err := consensus.msgSender.SendWithRetry(
 		consensus.blockNum, msg_pb.MessageType_ANNOUNCE, []nodeconfig.GroupID{
 			nodeconfig.NewGroupIDByShardID(nodeconfig.ShardID(consensus.ShardID)),
-		}, p2p.ConstructMessage(msgToSend)); err != nil {
+		}, p2p.ConstructMessage(msgToSend), true); err != nil {
 		consensus.getLogger().Warn().
 			Str("groupID", string(nodeconfig.NewGroupIDByShardID(
 				nodeconfig.ShardID(consensus.ShardID),
@@ -300,10 +300,13 @@ func (consensus *Consensus) onCommit(msg *msg_pb.Message) {
 	if !quorumWasMet && quorumIsMet {
 		logger.Info().Msg("[OnCommit] 2/3 Enough commits received")
 
-		go func() {
-			// TODO: make it synchronized with commitFinishChan
-			consensus.preCommitAndPropose(blockObj)
-		}()
+		if !blockObj.IsLastBlockInEpoch() {
+			// only do early commit if it's not epoch block to avoid problems
+			go func() {
+				// TODO: make it synchronized with commitFinishChan
+				consensus.preCommitAndPropose(blockObj)
+			}()
+		}
 
 		consensus.getLogger().Info().Msg("[OnCommit] Starting Grace Period")
 		go func(viewID uint64) {
diff --git a/consensus/threshold.go b/consensus/threshold.go
index 503185f3b..f9ced1139 100644
--- a/consensus/threshold.go
+++ b/consensus/threshold.go
@@ -74,6 +74,7 @@ func (consensus *Consensus) didReachPrepareQuorum() error {
 			nodeconfig.NewGroupIDByShardID(nodeconfig.ShardID(consensus.ShardID)),
 		},
 		p2p.ConstructMessage(msgToSend),
+		true,
 	); err != nil {
 		consensus.getLogger().Warn().Msg("[OnPrepare] Cannot send prepared message")
 	} else {
diff --git a/consensus/validator.go b/consensus/validator.go
index 7655da547..a692d3969 100644
--- a/consensus/validator.go
+++ b/consensus/validator.go
@@ -229,7 +229,11 @@ func (consensus *Consensus) onCommitted(msg *msg_pb.Message) {
 		Uint64("MsgViewID", recvMsg.ViewID).
 		Msg("[OnCommitted] Received committed message")
 
-	if !consensus.isRightBlockNumCheck(recvMsg) {
+	// Ok to receive committed from last block since it could have more signatures
+	if recvMsg.BlockNum < consensus.blockNum-1 {
+		consensus.getLogger().Debug().
+			Uint64("MsgBlockNum", recvMsg.BlockNum).
+			Msg("Wrong BlockNum Received, ignoring!")
 		return
 	}
 
@@ -244,7 +248,7 @@ func (consensus *Consensus) onCommitted(msg *msg_pb.Message) {
 		return
 	}
 	if !consensus.Decider.IsQuorumAchievedByMask(mask) {
-		consensus.getLogger().Warn().Msgf("[OnCommitted] Quorum Not achieved.")
+		consensus.getLogger().Warn().Hex("sigbitmap", recvMsg.Payload).Msgf("[OnCommitted] Quorum Not achieved.")
 		return
 	}
 
@@ -272,14 +276,23 @@ func (consensus *Consensus) onCommitted(msg *msg_pb.Message) {
 
 	consensus.FBFTLog.AddMessage(recvMsg)
 
-	if recvMsg.BlockNum > consensus.blockNum {
-		consensus.getLogger().Info().Msg("[OnCommitted] low consensus block number. Spin up state sync")
-		consensus.spinUpStateSync()
-	}
-
 	consensus.aggregatedCommitSig = aggSig
 	consensus.commitBitmap = mask
 
+	// If we already have a committed signature received before, check whether the new one
+	// has more signatures and if yes, override the old data.
+	// Otherwise, simply write the commit signature in db.
+	commitSigBitmap, err := consensus.Blockchain.ReadCommitSig(blockObj.NumberU64())
+	if err == nil && len(commitSigBitmap) == len(recvMsg.Payload) {
+		new := mask.CountEnabled()
+		mask.SetMask(commitSigBitmap[bls.BLSSignatureSizeInBytes:])
+		cur := mask.CountEnabled()
+		if new > cur {
+			consensus.getLogger().Info().Hex("old", commitSigBitmap).Hex("new", recvMsg.Payload).Msg("[OnCommitted] Overriding commit signatures!!")
+			consensus.Blockchain.WriteCommitSig(blockObj.NumberU64(), recvMsg.Payload)
+		}
+	}
+
 	consensus.tryCatchup()
 	if recvMsg.BlockNum > consensus.blockNum {
 		consensus.getLogger().Info().Uint64("MsgBlockNum", recvMsg.BlockNum).Msg("[OnCommitted] OUT OF SYNC")
diff --git a/consensus/view_change.go b/consensus/view_change.go
index 7b8cb42a4..1a94f2892 100644
--- a/consensus/view_change.go
+++ b/consensus/view_change.go
@@ -265,6 +265,7 @@ func (consensus *Consensus) startViewChange() {
 			[]nodeconfig.GroupID{
 				nodeconfig.NewGroupIDByShardID(nodeconfig.ShardID(consensus.ShardID))},
 			p2p.ConstructMessage(msgToSend),
+			true,
 		); err != nil {
 			consensus.getLogger().Err(err).
 				Msg("[startViewChange] could not send out the ViewChange message")
@@ -294,6 +295,7 @@ func (consensus *Consensus) startNewView(viewID uint64, newLeaderPriKey *bls.Pri
 		[]nodeconfig.GroupID{
 			nodeconfig.NewGroupIDByShardID(nodeconfig.ShardID(consensus.ShardID))},
 		p2p.ConstructMessage(msgToSend),
+		true,
 	); err != nil {
 		return errors.New("failed to send out the NewView message")
 	}
diff --git a/node/node_syncing.go b/node/node_syncing.go
index 77d2aa8ca..7e5fab3b6 100644
--- a/node/node_syncing.go
+++ b/node/node_syncing.go
@@ -260,7 +260,7 @@ func (node *Node) doSync(bc *core.BlockChain, worker *worker.Worker, willJoinCon
 		utils.Logger().Debug().Int("len", node.stateSync.GetActivePeerNumber()).Msg("[SYNC] Get Active Peers")
 	}
 	// TODO: treat fake maximum height
-	if node.stateSync.IsOutOfSync(bc) {
+	if node.stateSync.IsOutOfSync(bc, true) {
 		node.IsInSync.UnSet()
 		if willJoinConsensus {
 			node.Consensus.BlocksNotSynchronized()
@@ -542,5 +542,5 @@ func (node *Node) GetMaxPeerHeight() uint64 {
 
 // IsOutOfSync ...
 func (node *Node) IsOutOfSync(bc *core.BlockChain) bool {
-	return node.stateSync.IsOutOfSync(bc)
+	return node.stateSync.IsOutOfSync(bc, false)
 }