I’m having similar problems and I only have 6 motions sensors. I get false alarms every week, from different sensors! It’s almost as if they take turns producing false alarms. So much for sticking with Samsung branded sensors (well, smartsense).
I have no solutions so far, other than dismissing these annoying false alarms.
And no, I don’t have pets. There are no insects crawling. And the thermostat is off.
Motion detectors aimed at sun-lit areas, heat sources (furnace heat etc) or objects moved by HVAC (curtains near vents) may produce false alarms. I had similar issues that I resolved by relocating the sensor to cover the protected area from a different angle or opposite wall.