1: One person provides an agent for another.
2. Two people are on the same local area network or the same computer.
The former is very unlikely.
Supplement: to the comrade who talks about QQ. . .
This port can be changed at will, understand?
Plus: the other port can be modified by some software, and what you see will definitely be different, but you said that one port is displayed and the other is not displayed. What is not displayed should be logging in with multiple QQ numbers on the same computer at the same time. The port will be displayed for the first login, but not necessarily for the subsequent logins.