This being the Internet, I'm probably here just to complain about something. This being the Internet, here I go.
Some time back, my summons started failing with the "Unable to drive on public roads" error. Being in the middle of a parking lot, this was mysterious. Research ensued, leading me into the OpenStreetMap universe. I investigated, and found that the lane adjacent (but not connected to) my parking lot was marked as public. So, after checking the city's GIS maps and verifying that it was on private property, I made an edit. An hour or so later, I tried a summon and voila! It worked! My position as an Internet Influencer was secure.
Fame is fleeting however, and very soon thereafter, the summons resumed failing with the same message. I checked OSM to see if my edit was still there and it was. I understand there are a variety of map sources and I'm wondering if OSM has been bumped down in priority, because the lane in question still shows as a roadway on the nav display. This is not an entirely satisfactory explanation though, because again, my lot is not connected in any way to the lane, so no matter what it's marked as, it should not interfere.
If you've had experience with OSM, maybe you wouldn't mind taking a look. The image I've attached shows the url which I think will get you to my location, as well as a) where I usually park (red box), b) where summon fails (red squiggle), c) where summon succeeds (green squiggle), and the usual route (blue track to blue X). The lane I edited is Mimi Lane. Thanks.