Frame Change Threshold: Lower to 0.1% to start, move up after you start getting trigger events.
Motion Gap: Lower to 2 Seconds. It is the time from the end of one event to where it will allow a new trigger.
Capture Before: Increase to 5-10 otherwise you would get a total of 3 frames only.
Capture After: Increase to 5-10, same as Capture Before
Minimum Motion Frames: set to 2, otherwise it will only trigger after it sees 20 consecutive frames with changes.
Show Frame Changes turn On. It will give you an indication of where it sees frame changes.