I came across the same bug too. Hope it would be settled.
It is noteworthy that the additional ports tend to be default ones if the ports set in the "server.prosperities" are not default ports.
Thank you very much for your response. With your help, the problem has been settled.
When I set the first port "19132" and "19133",and the second port ""19134" and "19135",both of the two server runs well. It turns out that the best choice is use ports starting from the default one "19132" and "19133" and progressively increase the numbers like "19134,19135"... and start the servers in a proper order, then all the servers run properly in the end.
Came across the same problem too.
This kind of problems often happen when the server has been worked for a while. So restarting the server can solve the problem temporarily.