Using android sdk for monitor using background service in android, we found a behaviour is that enter region is triggered multiple times, if you include exit region event you will notice exit and enter region event is triggered rapidly even though you are near to the beacon and without physical movement.
Tested this across various from android 4.3 onwards with multiple devices.
Beacon os is updated to latest while the settings is as below.
Strength : 7 meter
Broadcasting interval : 500ms
Tried with various settings it does not really matter actually this happen consistent at indoor.
Do you have any clue ?