Reproduction steps:(Gif below)
1) Open users submitted project and build it twice.
1.1) Alternatively you can run three copies of a project in three Editors.
2) Go into play mode in the editor and hit "LAN server Only(S)" UI button.
3) Run one of builds that you created or go into playmode in another Editor.
4) Click "LAN Client(C)" UI button. Then move around with the ball using arrow keys.
4.0) Collapse Console of Editor that runs server.
4.1) Notice NetworkServer.GetConnectionStats are printed.
4.2) Clear the console, you should see three collapsed logs piling up.
5) Repeat step 3 , 4, 4.1 and 4.2 with other Editor/Build.

Expected result: After your last input data should not be added up any more and clearing console should leave a few logs piling up.

Actual result: After your last input data keeps on being added - you can see that by a buildup of a new logs in the Console of the Editor that runs Server.

Note: Disconnecting one user brings things back to normal.

Reproduced with: 5.4.0b3, 5.3.2p1, 5.2.4f1, 5.1.4f1