There's maybe a 10-foot difference between what DomoPad has and what Maps has.
I'd say that is about as accurate as a phone is going to get! Okay, so just off-hand, though not definitive, it doesn't sound like the same type of issue you were seeing with Google Photos. Let me think what else we can do in order to debug this.
I was out for a lunch today, and the system worked fine for leaving and arriving home. Fourteen minutes after arriving home, the system once again spontaneously activated the Leaving Home and then a minute or so later, the Arriving Home activity. At the same time, I got the notification from MacroDroid that the departure geofence set in that app had been activated. That means that two separate apps are being triggered by this problem. The conclusion is that it likely is phone/OS specific, since it isn't known to occur with other phones.
Battery saver mode is off, never used it. Battery level is rarely under 50% at home. In the car the phone is sitting on an inductive charger which keeps the level up, it always seems to be over 80%. I drove out to a park to ride my mountain bike this morning, and the exit geofencing error happened with the radius set for 250 meters. No SIM chip was installed (it's in the iPhone for now, I have an additional SIM coming later this week). No error on entering area.
For whatever reason, my LG phone (my handheld computer, really, since it very rarely gets used as a phone) has behaved itself and triggered the Enter and Exit functions as it should from within DomoPad. for the last few days. The only change that has been made to the device is to install a new nanoSIM with a new phone number. I fail to see how this would affect the GPS readings. The old SIM was swapped back and forth with an iPhone. I don't see how any settings baked into the SIM could make a difference.
That is a great point - if your phone is relying on aGPS (assisted GPS) then it could be affected by the presence of and, maybe, something within the SIM itself.
