Can XBee 3 Pro End Device rejoin XBee Zigbee network after Coordinator rebooted

Question

Hello
I have seen a similar question for 802.15.4, but could not find answer for Zigbee network.

My question is, for an XBee 3 Pro Zigbee configured as an End Device (SM=4 Cyclic Sleep), if the coordinator loses power for several minutes or hours so is not accessible when the End Device wakes from cyclic sleep, then the Coordinator is powered again and has started a network again, can the End Device rejoin the network next time it wakes from sleep?
The Coordinator in my case is Digi XBee Gateway (Ethernet + WiFi), from the XBee Zigbee Cloud Kit.
So far, I have found that the End Device does not rejoin the network. I want to avoid turning End Device's battery off and on to make it join the network after Coordinator restarted (which works), because End Device is in an inaccessible place.
If this is possible, what options do I need to change on the End Device or Coordinator? XBee 3 Pro Zigbee is running latest firmware (100D).
Many thanks

Answer 1

If a Zigbee end device is unable to communicate with its parent after 3 times in a row, it will perform a soft re-join. If that fails three times in a row, then it will go to a full join process till it is able to join.

If the router has the Network Watchdog timer enabled, it will also go into a full join if it is not able to hear form the Coordinator within the NW time frame.

Answer 2

SOLVED. I found the answer by reading the documentation. If an XBee 3 Pro Zigbee configured as an End Device (SM=4 Cyclic Sleep) leaves the Zigbee network it won't rejoin, and the AT parameter "Association Indication" (AI) gets a non-zero value, e.g. 36 decimal.
In microPython running on this XBee I detected AI non zero, then set CB to 1 which is equivalent to one press of Commissioning Button. After several seconds, the XBee rejoined the network, as shown by AI returning to 0 (having been through the value 255 decimal which means it is still initalizing).