Unknown reset to factory default

I used Xbee XB3 for my wireless handheld device for reading remote signal.
I have encountered a problem for a while. I could not find out why.
The handheld device is powered by battery. When the battery almost running out of power, then I change a new set of battery.
It seems also reset the xbee to factory default. then my system could work anymore.
Any one know why and can help me ?

Sounds like you are getting the radio below VMIN.

I have the same problem with Xb3-24Z8PT-J, did anyone solve it?

Similar problem. How can we protect the XB3 when the battery is approaching or falling below VMIN?
Will holding the RESET pin low help?

It is not recommended to hold any device in a reset state. It would be better off to not power on the radio if your batteries voltage drops below VMin or use a voltage regulator.