This can be caused by a variety of reasons. For example:
Sensors may place a person within a room. This position will take priority if it is the most recent location the person was seen to be actively occupying.
Wired data may place a person within a room if a docking station of additional workstation is being used.
The utilization source that has detected the person may be associated with the incorrect space. If you believe this is the case, then contact your System Administrator.