Am I understanding correctly that you are using the built-in presence features of SmartThings?
If you were already using Tasker + Geofencing (AutoLocation?) for something else, have you considered reporting your own presence status using Tasker + SharpTools?
Other users have indicated that when they have something else accessing location services on the phone, they’ve actually seen more reliable status updates from SmartThings. I could never get the built-in SmartThings presence to accurately report my location, so I gave up on it long ago.
Also, what did you mean by your “geofence log”?
Note that just because you have internet now doesn’t mean you necessarily had internet connectivity when the geofence was exited. I haven’t seen the internal workings of the SmartThings geofence code, but I know that some users who have created their own custom presence have added retry logic to their custom presence as they found that the command could fail when they were transitioning from Wifi to Cellular (or vice-a-versa):