Cam not capturing all motion

I have a wireless stick up cam pointed at my car. It never records motion when I leave or return. I know it’s working since it captures people walking by. It’s set to highest sensitivity and there’s no option in the menu to set a motion zone. Any advice?

I’ve noticed and read that motion is best detected if something crosses its path. When something comes straight on I see it fail. A slight angle will help so objects move across it’s field of view. Hope this helps.