The sentry icon only shows up when car is in park, since it only works in park. When moving, you want the dash cam recording instead. Once you're parked, the sentry icon will show up. And if you want it to record, just click on it and a red dot would appear in the middle. If it records something, and you want to see it in the car, you need to launch the viewer from the dash cam icon menu. I bought our Tesla less than 2 weeks ago, so I'm learning too. Ha ha. Sometimes the issue is with the USB stick, so format it first, as mentioned. Good luck.