This article describes the issue when you see the wireless clients are not matching to the rooms or areas they are supposed to be in.
NPM version 11.5
There are two things why this issue occurs:
The size and scale of the map must be as close to precise as possible. Based off the manner in which Wireless Heatmaps triangulates the endpoints off the RSSI signals from the APs on your map. If the scale is incorrect for the size comparison on the map, then the application will not know to compensate for the distance.
Moving the AP outside the location of the map or moving the AP on the map outside of the actual physical placement will also throw off calculations. These portions need to be as precise as possible to insure that an endpoint is in the room it is supposed to be and not in a room nearby incorrectly.