Why do lights turn on but no motion recorded on floodlight cams?

Sometimes I see the lights on my outdoor floodlight cams turn on and assume there’s a motion event that triggered it but, in the app there’s no motion event recording and no ring notification. Why would the lights be triggered without motion and a motion event recording? This happens a lot. Also conversely, there are plenty of times when a motion event is recorded and the camera’s lights never turn on at any point during the recording. The entire motion triggered video clip is in color night vision mode because the floodlight cam’s lights never turned on. Why is that?