My cameras are pretty moody about when they will bother to sense a person in front of them and when not. So i got myself a little bog-standard Sonoff motion sensor, and put it in a bird house to protect it from the elements.
I installed it today and all day long, every few minutes, it's been detecting invisible "people". Active followed by inactive in pairs all day long. It finally calmed down as the sun went in, and so I went out to test it. Walked past a few times. Checked the events, and nothing. Hmm. Checked the logs and it had sent a solitary "Inactive" log entry, which obviously didn't count as an event as there was no change from its last inactive state. How contrary can these little machines be????
Will be interesting to compare the Sonoff sensor to the small inexpensive Tuya _TZ3000_msl6wxk9 that I know you already have.. : ) You can try reducing this particular model Tuya PIR sensor sensitivity to medium or low and see whether this will have any effect on the false triggering when placed outdoor.
Ooops, sorry, my bad - I was wrong about you possessing exactly this sensor model.
From what I have read so far, it is difficult fo filter false triggering caused by direct sunlight on PIR sensors.
Probably, the new radar sensors will be a solution, although still rather expensive,
I have a bunch of sonoff sensors and honestly my experience is mixed. They're very inexpensive but I've found them to be less than 100%.
I've had good luck with Hue outdoor motion sensors. I have a couple of them on my front porch and I use the zone motion controller app to combine them. Never a false alarm (when using both) and as far as I can tell they have never failed to detect motion. In fact I just ordered another four of them for the perimeter.
I do have one, but because of its downward sensing shape, I have only been able to use it in one place - on top of a garden store box with fencing around to stop foxes getting onto the box and being picked up. Had so many interrupted nights with foxes setting off the motion sensors - or eating them
Might be a candidate for a bird house, would keep it under control a bit.
Having false positives for a really long time I decided to throw another motion sensor at it and use them in a "motion area" ... both have to trigger to be a positive. Now I have 100% accurate detection.
The only thing this sensor does is play something on the speaker.. a drum flourish.
Yesterday, I got a really good "test"... and thought I had my first false positive. People were expected over but when the sound played, but no doorbell/knock, I thought I'd see if I was getting my first ever false positive since adding the 2nd sensor. I opened the door and there's no one there. Solid "proof" of the false positive. I had pictures in my head of how I can make the logic better.
Then it happened a 2nd time! And my wife said.. "it's the dog, who locked the dog out front?" (Bringing groceries in from the garage, the dog went out and we closed the door with him outside. He was running between the front door and the side door, looking for a way back in.)
So... still got a 100% accurate detection going since adding the 2nd sensor.
I just installed a Philips Hue Outdoor Motion Sensor. It uses AA batteries, has a nice mounting kit, and provides Motion, Temperature, and Illuminance data. It is directly paired to my Hubitat hub. The Hubitat driver has some pretty nice features for setting the sensitivity of the motion sensing aspect. I have noticed that it does pick up our cars in the driveway, even after dialing the sensitivity to be pretty low...but as you stated, a few false motion reports aren't the end of the world. It does pick up people as they walk up to our front door very reliably.
Motion sensors like this are pretty much all PIR sensors. So when the "see" something warm that is different enough from whatever was there before, whether it's a person or a sunlight, they're going to go off--probably more so for sunlight when you're outside since there's a lot of it, it's very warm, and it's probably changing constantly with clouds coming and going, wind and reflections and other objects, and what have you. Putting it in a birdhouse like you did might help a bit, aside from the narrower field of vision it might have (if the entire sensor is inside), but most dedicated "outdoor" sensors have both a narrower field of vision in their lens and the ability to adjust sensitivity--thinking of things like the Hue Outdoor Motion Sensor and the Zooz ZSE29, two standalone units I can think of. At least one of these also still recommends placing them in a semi-protected area.
But, like you, I've also used a Sonoff motion sensor outside. I figure it's cheap enough that I don't care if it breaks or my experiment fails. Mine are both somewhat protected from direct sunlight but do still have times when they send off event after event. I deal with that by using three sensors in this area (not all Sonoff, in my case) and requiring at least 2 to become active within a few seconds, coupled with Zone Motion Controller and a "false motion reduction" zone, in order for the zone sensor to become active. This works decently well for me though occasionally gets a few false positives for an hour or two certain times of the year. I could probably add more sensors to further reduce this or maybe require all three, but it's good enough for me as-is.
(FWIW, the Sonoff sensors to seem particularly more sensitive than others I've used, perhaps because of their large, protruding lens. My Z-Wave sensors outside go off less...sometimes so much less that they barely see me inside our outside, but that's another story. Ha.)
Another suggestion I've seen is to use beam-break sensors instead. I'm not aware of any that integrate directly into Hubitat, but any that just open/close a circuit when the beam breaks would work. If it's a very specific area, like a front porch, a pressure mat that does the same might work, too--something others have done on couches wired up to a Z-Wave contact sensor Hubitat-integrated alarm planel, etc.
You could potentially use the passive contact output of a beam break system to wire into a contact sensor with external terminals on it...(there are a coupole of zigbee and z-wave ones like that) That's predicate on the beam break sensor having the proper output wires of course