Settings EnableNextExpectedMsgSeqNum not works well

[BingerCoder]

FIXT.1.1
50SP2

When set EnableNextExpectedMsgSeqNum=Y,the tag 789 always equals to 2 when first time logon.

[DEFAULT]
SocketConnectHost=127.0.0.1
SocketConnectPort=1111
HeartBtInt=60
SenderCompID=xx
TargetCompID=xx
ResetOnDisconnect=N
ResetOnLogon=N
FileLogPath=fixlog
StartTime=04:00:00
EndTime=23:55:00

[SESSION]
BeginString=FIXT.1.1
FileStorePath=./sessions/
DefaultApplVerID=9
EnableNextExpectedMsgSeqNum=Y

@ackleymi Please check it ,thanks a lot

[BingerCoder]

// NextTargetMsgSeqNum returns the next MsgSeqNum that should be received
func (store *fileStore) NextTargetMsgSeqNum() int {
	return store.cache.NextTargetMsgSeqNum()
}

...

// Evaluate tag 789.
if s.EnableNextExpectedMsgSeqNum {
	if inReplyTo != nil {
		targetWantsNextSeqNumToBe, getErr := inReplyTo.Body.GetInt(tagNextExpectedMsgSeqNum)
		if getErr == nil {
			actualNextNum := s.store.NextSenderMsgSeqNum()
			// // Is the 789 we received too high ??
			if targetWantsNextSeqNumToBe > actualNextNum {
				// we can't resend what we never sent! something unrecoverable has happened.
				return RejectLogon{fmt.Sprintf("Tag 789 (NextExpectedMsgSeqNum) is higher than expected. Expected %d, Received %d", actualNextNum, targetWantsNextSeqNumToBe)}
			}
			nextSeqNum := s.store.NextTargetMsgSeqNum()
			logon.Body.SetField(tagNextExpectedMsgSeqNum, FIXInt(nextSeqNum+1))
		}
	} else {
		// We are sending a logon.
		nextseqnum := s.store.NextTargetMsgSeqNum()
		logon.Body.SetField(tagNextExpectedMsgSeqNum, FIXInt(nextseqnum+1))
	}
}

NextTargetMsgSeqNum means next MsgSeqNum that should be received
if it equals to the NextExpectedMsgSeq?needn't +1?

[BingerCoder]

if s.EnableNextExpectedMsgSeqNum {
	if inReplyTo != nil {
		targetWantsNextSeqNumToBe, getErr := inReplyTo.Body.GetInt(tagNextExpectedMsgSeqNum)
		if getErr == nil {
			actualNextNum := s.store.NextSenderMsgSeqNum()
			// // Is the 789 we received too high ??
			if targetWantsNextSeqNumToBe > actualNextNum {
				// we can't resend what we never sent! something unrecoverable has happened.
				return RejectLogon{fmt.Sprintf("Tag 789 (NextExpectedMsgSeqNum) is higher than expected. Expected %d, Received %d", actualNextNum, targetWantsNextSeqNumToBe)}
			}
			nextSeqNum := s.store.NextTargetMsgSeqNum()
			logon.Body.SetField(tagNextExpectedMsgSeqNum, FIXInt(nextSeqNum+1))
		}
	} else {
		// We are sending a logon.
		nextseqnum := s.store.NextTargetMsgSeqNum()
		logon.Body.SetField(tagNextExpectedMsgSeqNum, FIXInt(nextseqnum))
	}
}```

if inReplyTo != nil nextSeqNum+1,else nextseqnum