We have an Android that works fine all the time and an iPhone 6s that never seems to leave the house but always returns at a new time. I finally got rid of the app sensors and started using Life360. It’s an app issue. iPhone works 100% now. No changes to anything on the phone other than switching from Smartthings App to Life360 App. It’s just better at determining where the phone really is. The kids have the fob presence sensors and those seem to work fine too.