Nginx Webserver

I am new to this space. I want to know if we have our passbolt server (installed in ubuntu server) in company itself using a 192.168.x.x ip address and everything is being used intern, then why is the passbolt-ce-server causing internet problem?
As soon I start the nginx.service the internet connectivity starts getting slow. How can i find out where the webserver is sending the packets, as it is causing Internet Bandwidth problem.