If the Teacher Tracker software is not switching, check:
The calibration process takes only a few minutes to complete, always re-calibrate the system if you move the cameras to a new location, or when you changed their position within the same classroom.
Also we would strongly recommend you to read the Basic CamDirector® tips
And finally be aware that the goal of the CamDirector is not to track the teacher as much as possible, but to give a calm and a pleasant to watch video on the output. The system prevents too much switching between cameras during a typical 1,5-hour college lesson.