Security Light Suddenly started working

I moved into a new house a few months ago. The previous owner left the smart outdoor camera, it showed no signs of power and I wasnt too bothered about using it so it's been sat for a few months. Suddenly today when I came home the floodlight turned on, or had turned on just before I came home. The power has been on all the time as another light is on the same circuit as it. Tried to add it in the app to no avail. Just very confused why it suddenly burst into life today. It doesn't seem to turn off, and when I cycle the power, it just comes on straight away and the lights stays on. Any ideas? How can I either disconnect it, or get it set up? I do have the QR code.