iPhone 6s Pluig presence detection problems (continued)

My wife’s presence detection has been flaky for the last few months. I have triple checked the following

Background app refresh enabled
Low power mode disabled
Location services are on
the geofence is at the minimum diameter

In the past, her tile would show she is home when she is not home about 50% of the time. I have yet to remember a time when it said she was gone when she was actually home.

To correct his temporarily, she would open the app, her tile would dim on my phone and say she is gone. Today, SmartThings said she was home when we were 20 miles away. I asked her to please stop closing the app, and got a look and she said the app IS open, just in the background. After I crawled out from under the table and apologized, it all works fine once again.

I use this for the Nest thermostat and front door lock. As long as SmartThings thinks she is home, the HVAC runs more and the front door is not locked.

As soon as she brought the app to the front, her tile changed to gone. The app was not closed.

I have restored her phone several times from the apple cloud, even went as far as deleting the phone in the IDE and reinstalling it.

My guess there is something with the phone, since my presence detection is always correct.

Perhaps I am missing something. Reading about presence detection does not highlight this particular issue. All I can discern is that presence detection is not an exact science with the iPhone.

@Tom_Guelker
I have the problem you are speaking of several times. In general though, I have found the delays in using our iPhone 6s to be unacceptable and very unreliable for geofencing.

Brian