Does this happen after someone entered or exited the room?
Yes, it only happens after someone entered or exited the room.
Then increase the Maybe Occupied Timeout in the Occupied Timeouts Menu for the Room Scene in which this occurs. You may want to increase the time by half and see if the problem continues to occur.
No, it happens while someone is just sitting quietly in the room.
Then, you can do one of two things:
Increase the Maybe Occupied Timeout in the Occupied Timeouts Menu for the Room Scene in which this occurs, or
Increase the Area Sensor sensitivity in the Sensor Sensitivity Menu.
It may be best to use both methods. The first time it happens, try the first option of increasing the Occupied Timeout for the Room Scene in which this occurs by at least half, or, possibly even doubling the time.
Note that if the Home Positioning™ System was designed well, then
Every entry into the room has an Entry/Exist Sensor and
All Entry/Exist Sensors are working well and
You do not have any Bleeding Area Sensors,
If this is true for this room, then you should be able to increase the Occupied Timeout time to infinity. However, once in a rare while, someone usually finds away to exit the room without being detected by an Entry/Exit Sensor (i.e., a Beam Out), and, thus, the Occupied Timeout will be responsible for turning off the room on that occasion. Therefore you do not want to make the Occupied Timeout too long.
If the above conditions are not true, then as you increase the Occupied Timeout you will start to have the problem of "The lights don't turn off quickly enough when everyone leaves the room". When that happens, try to fix the problem using that troubleshooter.
The second time it happens, try increasing the sensitivity of the Area Sensors. If there is more than one Area Sensor in the room, only increase the sensitivity of the one pointing at the person who was sitting so quietly. You will know you have increased the sensitivity too much if "The lights turn on when no one is in the room" or "The lights don't turn off quickly enough when everyone leaves the room".
After you have lengthened the Occupied Timeout time a few times and increased the sensitivity of the Area Sensors via the Sensor Sensitivity Menu a few times, if you still have a problem, then you need to increase the Analog Sensitivity of the Area Sensors.