xctu doesn't set xbee, xbee pro back to default

Hi i am relatively new to zigbee communication and i know that it i set dl,dh of end device side to 0, it will only communicate to coordinator. But when i tried default, every at section change except DL,DH of module. I mean, i can’t change DL, DH back to 0, other values are okay. I tried it on xbee pro which is coordinator but it doesn’t change either. What could be wrong? I use xctu 6.1.0 version. Does anyone can fix figure out this problem?How can i change DL, DH of xbee back to 0 using xctu 6.1.0 version?

Instead of providing a value of 0, you need to provide a 64 bit value of 0’s. One for each place holder. Then click on write.