What is the best distance to keep the Beacons apart?

However from our test results we’ve realized that ranging Beacons close to each other is confusing for the Estomote app to pick up the nearest Beacon. The Beacons are bouncing inside the app. I would like to know the meters to keep the Beacons apart.
I have attached the screenshot from the Estimote testing app showing us the Beacons bouncing.
It seems like the distance to a Beacon is not accurate.