After testing and checking all permissions, battery settings, and HC3 configuration, I found the actual reason geofencing is not working on my phone (Android 16): Android 16 introduces a new background‑location and geofence API. The current Yubii Android app has not been updated to support this new API. Because of this, Android 16 simply ignores the geofence registration request from the Yubii app. As a result: Yubii never appears in “recent location access”