My security camera has suddenly started reacting to movement and making recordings when the system is in DISARMED mode. I have triple checked the settings, and they have not changed. The camera is set to not do anything automatically when the system is disarmed. It worked like this for about a month before suddenly changing its behaviour. The issue is deeply problematic for me, since the camera is in a hallway where people must be able to come and go without being recorded.
I recommend also checking for any linked devices that you might have setup for a device to start recording when another detects motion.