My Nissan Sentra experienced unintended forward movement while Reverse was selected. After restarting the vehicle and shifting back into Park and then Reverse, the vehicle moved forward instead of backward, and the brake behavior became abnormal. This caused a minor collision. The condition has been reproducible, and I have video evidence documenting the issue. The vehicle is currently being held, and I was informed that repairs should not begin until Nissan inspects the vehicle and retrieves diagnostic/event data. I am submitting this as a potential safety defect involving unintended vehicle movement, shifting, braking, and vehicle control.