Request Collaboration change default port?

Hi there,
Our Request Collaboration isn't working (warning when another technician is in the same ticket).
I've done some searching and found that the server.xml needs a connector entry with port 8081.
Using netstat I can see that port 8081 is already is use by another windows application (check_mk_agent.exe).

So we've changed 8081 to 8082 in the server.xml. If two technicians go to https://servername:8082 and look at the same ticket they see the notification.
But when using the normal link ( on port 443 I suppose) we don't get the notification.

Can we use another port for the request collaboration? Do I have to edit another file to point it to port 8082?

Thanks,
Nick