I've verified in the map "home" is my address, when parked the app is at that address. Am i missing something?
Let me see if I can condense this so it does not become a TL;DR thing.
What's the saying in real estate? Location, location, location... Well in this scenario location may not be what you think.
On your laptop or computer, open maps.google.com in your browser and enter in your street address, where you live. You should see a red pin dropped on a map, zoom in and see your home and your neighbors. Where is the pin exactly? For me it is the center of my home as drawn on Google's map, but is that correct? You'd think so but it is not entirely accurate.
Right click on that pin and in the pop up menu you should see a set of coordinates appear at the top of that popup, left click on them to select and copy to the clipboard.
Open a new web browser window, go to maps.google.com and now paste in those coordinates instead of your address. Notice where the red drop pin is now shown. For me it is on the street at end of my driveway, not the center of my house like before. That is the real location being offered up by Google maps for your address. If you think about it, this makes sense since it comes from the vehicle they are driving around the neighborhoods do the street view and other stuff. They are not taking a location on your property, just on the street in front of your home.
Right click on that last dropped red pin at the end of your driveway (I assume, it is for me) and the last item in the pop up menu should be measure distance, select it. Now click where you park your car. It should show you the distance between the two locations. Is this distance large? More importantly, how close is your parked MY to your closest neighbor?
GPS location will have some degree of error, all depends on the quality of the fix. For my iPhone it is around 16 feet when I checked, so location shown on my iPhone can be off by as much as 16 feet, no idea what it is like for the MY, I do not have access to that data on my MY. But if you are parked close to the property line with your neighbor, or inside a garage, could the error in location place you at their address instead? Or does it increase the distance from that pin drop on the street? Tall buildings, tree cover, etc. can hamper the GPS accuracy, less satellites in view, less accurate position, more chance for your MY to think it is somewhere it is not.
To hazard a guess, the MY is probably using the GPS coordinates defined as your home address to define the center of a circle, and then using some distance from that point to define the radius of that circle, aka a geofence. If the current GPS location of your MY is inside this circle, then it is home, otherwise it is not. No idea if this is how they implemented it, or if they just find the street address based on your current GPS and use that instead. When you have access to a navigation database, more than one way to implement this check. For simpler installations with no navigation database, it is usually some sort of circle or box drawn around a position to fence in the okay area, and if you venture outside this fenced area, then trigger an alarm or whatever.
I know that if you press the drop pin on the Tesla navigation screen while parked at home, it seems to update your driver profile with that location, I can watch the screen saving/updating my profile after I press it so perhaps that is overriding the navigation GPS position with this position? If not, then I'm not sure why it is saving my profile every time I do that at home. I've never had any sentry issues when parked at home and home is excluded. So if this appears to be better with a later software version, perhaps they are adjusting the home position logic to make it more forgiving, a larger radius on that circle so to speak.
Not sure if that helps or not. Trying to shed some light on what could be going on here.