Phantom Car

Today, I received a notification on my cell phone and on Alexa, that there was motion activation from my driveway camera. My son had just arrived home and was driving into the garage. A couple of minutes later, when I checked my Ring history on my cell phone, there was no notification of the activation. This has happened before. Sometimes my Ring camera will detect the car driving out, but will not detect it coming in. My front door Ring doorbell did the same thing last week. A package was delivered, but it did not capture the event. Why are these phantom events not being captured? And no, it has nothing to do with my wi-fi signal, which is working at close to 100%, nor the network channels. Scratch those off as culprits. This only happens intermittently.