v4.0.0 TCP ACKed unseen segment

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Hi experts,

For the TCP Analysis , Version 4.0.0 vs 3.6.8 , why is there such a difference?

4.0.0 : [TCP ACKed unseen segment]  count 7

3.6.8 ：[TCP ACKed unseen segment]  count 3

Version 4.0.0 (v4.0.0-0-g0cbe09cd796b)

No. Time    Source  Destination Protocol    Stream  Seq NextSeq Ack Length  Info
1   19:59:17.739060000  10.0.0.1    172.16.0.1  TCP 0   0   1   0   66  50000 → 445 [SYN] Seq=0 Win=8192 Len=0 MSS=1418 WS=256 SACK_PERM
2   19:59:17.744753000  172.16.0.1  10.0.0.1    TCP 0   0   1   1   66  445 → 50000 [SYN, ACK] Seq=0 Ack=1 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM
3   19:59:17.744869000  10.0.0.1    172.16.0.1  TCP 0   1   1   1   60  50000 → 445 [ACK] Seq=1 Ack=1 Win=66560 Len=0
4   20:00:14.600295000  10.0.0.1    172.16.0.1  TCP 0   20037   20289   23628   306 [   ] [TCP Previous segment not captured] 50000 → 445 [PSH, ACK] Seq=20037 Ack=23628 Win=66048 Len=252
5   20:00:14.606207000  172.16.0.1  10.0.0.1    TCP 0   23628   23816   20289   242 [TCP ACKed unseen segment] [TCP Previous segment not captured] 445 → 50000 [PSH, ACK] Seq=23628 Ack=20289 Win=131840 Len=188
6   20:00:14.606690000  10.0.0.1    172.16.0.1  TCP 0   20289   20510   23816   275 [TCP ACKed unseen segment] 50000 → 445 [PSH, ACK] Seq=20289 Ack=23816 Win=65792 Len=221
7   20:00:14.612473000  172.16.0.1  10.0.0.1    TCP 0   23816   24020   20510   258 [TCP ACKed unseen segment] 445 → 50000 [PSH, ACK] Seq=23816 Ack=20510 Win=131584 Len=204
8   20:00:14.612488000  10.0.0.1    172.16.0.1  TCP 0   20510   20618   24020   162 [TCP ACKed unseen segment] 50000 → 445 [PSH, ACK] Seq=20510 Ack=24020 Win=65536 Len=108
9   20:00:14.618430000  172.16.0.1  10.0.0.1    TCP 0   24020   24128   20618   162 [TCP ACKed unseen segment] 445 → 50000 [PSH, ACK] Seq=24020 Ack=20618 Win=131328 Len=108
10  20:00:14.618733000  10.0.0.1    172.16.0.1  TCP 0   20618   20710   24128   146 [TCP ACKed unseen segment] 50000 → 445 [PSH, ACK] Seq=20618 Ack=24128 Win=65536 Len=92

Version 3.6.8 (v3.6.8-0-gd25900c51508)

No. Time    Source  Destination Protocol    Stream  Seq NextSeq Ack Length  Info
1   19:59:17.739060 10.0.0.1    172.16.0.1  TCP 0   0   1   0   66  50000 → 445 [SYN] Seq=0 Win=8192 Len=0 MSS=1418 WS=256 SACK_PERM=1
2   19:59:17.744753 172.16.0.1  10.0.0.1    TCP 0   0   1   1   66  445 → 50000 [SYN, ACK] Seq=0 Ack=1 Win=8192 Len=0 MSS=1460 WS=256 SACK_PERM=1
3   19:59:17.744869 ...