Reducing false alarms

Region first, then sensitivity, then the person filter.

In rough order of effectiveness:

Draw a tighter region. Excluding a window, a TV, or a doorway to a busy street removes the cause entirely rather than trying to threshold around it.
Add exclude zones over specific troublemakers — a screen, an aquarium, a hanging plant near a vent.
Lower the sensitivity a step or two and watch for a day.
Turn on the person filter, which checks whether anything human-shaped is actually present before alerting.
Raise the cooldown so one long event produces one clip instead of many.

Common culprits: direct sunlight moving across a wall, headlights sweeping through a window at night, a television, ceiling fans, and pets.