Motion Detection

Hi, I’ve recently installed my first doorbell. On the whole it works quite well. I’ve tweaked the zones to make sure it spots false positives (dog walkers).However it seems to be intermittent on detection. For example it will pick up my wife leaving the house on a school run, but doesn’t pick her up returning 20 mins later. Similarly it won’t pick her up coming home from shopping, but then does pick her up getting the shopping out of the car. So watching the history her car magically appears and disappears throughout the day with no alert.So that gives concerns that there are other things not being picked up.Any suggestions?