Many device manufacturers build in addition to the already existing Android battery optimization system their own. These systems limit or disable the background work of apps that the user hasn't opened in a while to save battery, memory, and data.
As a result, the AT-ZONE app may malfunction and provide inaccurate location data.
To prevent this from happening, you need to configure the target device so that it does not deactivate the background work of AT-ZONE.