Not seeing back to back alerts

More than a few times now I’m not seeing video of a second alert when it happens shortly after the first. Example being I get an alert that someone is at door and see a package dropped off. A minute later the package is gone and I never saw who picked it up. Luckily was someone in the family. Another time a contractor was out back but then came inside and someone tried to get into their truck. It was not captured on video.