Why Are Some TCP Conversations Reported Twice?

Some TCP conversations are reported twice, what’s wrong?

First, make sure that the deduplication process is not configured too tightly. If the faulty TCP conversations keep being reported twice, then maybe the duplicated packets are altered in some way that makes them too different from the originals. For instance, some firewalls randomize the ISN of TCP connections (for security reasons). So if you mirror some traffic before and after passing through such a firewall, this traffic will be reported twice since their sequence numbers will be different.