Have two users currently using system. 1) admin-me and 2) parts-coworker.

I am the main computer in which I would need to be logged in before then can use. They have been getting booted out but shows still active. 

Other day is showed I was logged as "parts" but I am "sysadmin" ...in order to restart I had to reboot and do the "Connection Manager" Start and Stop service. ...

any idea what could be going on?