It’s known to happen. There could be a few things you can check to isolate the source:
- Pull out the battery and see if there are reports, if so then it’s the platform having ghosting issues (report it to ST support on the forum, there was a topic for ghosting created a few years ago)
- “reset” the device and try putting in new batteries
- Note that temperature variances can set off the PIR sensor (it’s basically looks for heat signatures). So check if your box has hot spots or where it’s mounted has hot spots in it’s field of view. For example, if you have a plumbing / heating pipe running behind the walls in the field of view of the sensor, that’s known to set off the motion sensor. You would probably need a heat gun or IR temperature sensor to detect heat spots in your room.
These can tricky to identify. I’ve seen one a motion sensor go off in the middle of the (cold) night when a car with a bright headlight drives by a window causing the headlight to fall squarely in the field of view of a motion sensor.
If all the above fail, get contact ZooZ support for a replacement it could be defective units