I live one house away from the entry to a very small cul-de-sac. I thus get to observe a lot of delivery vehicle round trips. What I have been noticing is that often I get just one direction of such a trip. Today, I looked at the Amazon delivery van very carefully. First off, in the event list, I have an event clocked at 2:44 in which in the clip I can see the vehicle coming up our street. I then noticed that there was no event clip for the Van leaving. I then looked at the playback capture. I see two one minute clips, one starting at 2:44 and the other at 2:46. Much to my surprise, in the 2:44 clip, there are no vehicles, despite the fact that I have a 30 second event clip at 2:44:03 which definitely has the Van. In the 2:46 clip I can see the Van leaving, so clearly the motion detection started the recording and caught it, but did not create an event! Conversely, motion caught the Van arriving and created an event clip, but despite recording a playback clip at the same time, it missed the Van.
So to summarize, here is what I see:
2:44 30 second event clip with Van visible from 2:44:01 to 2:44:03
2:44 1 minute playback with no Van visible from 2;44;00 to 2:44:59
2:36 1 minute playback with Van visible from 2:44:06 to 2:44:08