“End clip early if motion stops” is a camera setting designed to stop recording a motion clip if motion in the view stops before the clip is complete.
For example, you may have your motion clips set to record for 30 seconds after a motion is detected. If a passing car causes the motion, but there is no activity afterwards. With this setting off, you would receive a 30-second clip with no visible motion. With this setting on, you would receive a clip just a few seconds long.
You control the “End clip early if motion stops” setting in the Camera Settings screen.
Keep in mind that this feature may not always end the clip early under certain conditions.