xctu doesn't set xbee back to default setting

Hi, Im new to xbee and i know that if i set destination low, high to zero on the ‘end device’ side, it will only communicate with coordinator. I accidentally set end device side destination address low and high into different value, so i tried to set it back to default, which is 0, but xbee won’t change. The destination address of end device can be changed to every value except 0. I tried it on coordinator side but it was same, nothing changed. What is wrong with this xbee? I don’t know whether it might be xctu problem or not, because other people use xctu with old version. I use xctu version 6.1.0. Can someone plz figure out what might be wrong?

It is likely an X-CTU problem. In the console, can you go into command mode with +++ and set it yourself with ATDH0 ATDL0 ATWR? If not what radio is this, and what firmware version are you running?