Probably because the app is constantly scanning for beacons.
<a href="https:&#x2F;&#x2F;www.facebook.com&#x2F;business&#x2F;a&#x2F;facebook-bluetooth-beacons" rel="nofollow">https:&#x2F;&#x2F;www.facebook.com&#x2F;business&#x2F;a&#x2F;facebook-bluetooth-beaco...</a>