Geofency issue

I am having issues with my wife's iphone that sometimes update the ibeacons status in PHLocation and sometimes it does not.

She have an iphone 7 running 10.1.1, I have the same exact setup and mine keeps updating the status of ibeacons correctly.

Anyone have the same issue ?

p.s. There doesn't seem to be other Bluetooth issues with her phone, car bluettoth ok, speaker ok, stereo headset ok