Problem with XBEE PRO 60mw P24-AWI001

In XBEE PRO 60mw P24-AWI001 documentation for the distance has written 1 mile
But in reality less than that was 400ft
What’s the problem?

You need to have perfect RF LOS conditions. You also need to have the wire whip pointed directly up in the air and perpendicular to the radio.

You also need to use Unicast addressing and a location where the noise level is not very high.