CC2530: Rejoining Issue

Hi, I'm using CC2530 with ZStack1.2.2a as coordinator. I made a network with 10 end devices and no routers. All the devices are both IASZone and temperature devices. They report temperature every 15 minutes correctly. After some hours without IASZone activity I started moving the sensors. They worked correctly, but 4 of them stopped working after that last report. When I saw the sniffer capture I noticed they sent Rejoin request, coordinator answered Rejoin Response OK. The devices sent a few Data requests after that  and they completely disappear. Why did they send Rejoin request if they never left the network? Why didn't they continue working after the rejoin response? Is this an issue of the coordinator or the end devices? I attach the wireshark capture. We can use the device 0x2ac2 as example. Packet 53 is the last IAS notification. Packet 103 is Rejoin request and 115 is the response. Then there are some data requests and nothing else.Sniffer capture.rar