Pair Iris V2 contact sensor with an Xbee as the coordinator

I have an Xbee I’ve set up as a coordinator (using all the correct parameters) and I can get the sensor to join the network, but it issues a NWK Leave command after 4 seconds. Anyone have any insight as to what could be wrong? In the 4 seconds I can issue Active EndPoint request and Simple Descriptor request. I’ve even read the Manufacturer and Model number. It just won;'t stay on the network.