xbee3-24 zigbee random delay between transmission and reception

Hello, I am currently using two Xbee3-24 with zigbee 3.0 protocol: one is configured as coordinator and the other as router. The router is connected via spi to a pic24F microcontroller, I send a message from the pic via spi to the router which will send it via RF to the coordinator. In xctu, I can see that the coordinator has received the message but with a random delay. Each time my program runs, the message arrives at the coordinator after a random delay, the main problem being that this delay can be up to 10 minutes. Any idea why I have this problem. Any advice?

Sounds like your module is a sleeping end device. If that is the case, it would need to wake up and send the data to the parent router first. Then the router would send the data as soon as the network is free to send data over.